{"Address.sol":{"content":"//SPDX-License-Identifier: MIT\r\npragma solidity ^0.8.0;\r\n\r\nlibrary Address {\r\n    function isContract(address account) internal view returns (bool) {\r\n        bytes32 codehash;\r\n        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;\r\n        assembly {\r\n            codehash := extcodehash(account)\r\n        }\r\n        return (codehash != accountHash \u0026\u0026 codehash != 0x0);\r\n    }\r\n\r\n    function sendValue(address payable recipient, uint256 amount) internal {\r\n        require(\r\n            address(this).balance \u003e= amount,\r\n            \"Address: insufficient balance\"\r\n        );\r\n\r\n        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value\r\n        (bool success, ) = recipient.call{value: amount}(\"\");\r\n        require(\r\n            success,\r\n            \"Address: unable to send value, recipient may have reverted\"\r\n        );\r\n    }\r\n\r\n    function functionCall(address target, bytes memory data)\r\n        internal\r\n        returns (bytes memory)\r\n    {\r\n        return functionCall(target, data, \"Address: low-level call failed\");\r\n    }\r\n\r\n    function functionCall(\r\n        address target,\r\n        bytes memory data,\r\n        string memory errorMessage\r\n    ) internal returns (bytes memory) {\r\n        return _functionCallWithValue(target, data, 0, errorMessage);\r\n    }\r\n\r\n    function functionCallWithValue(\r\n        address target,\r\n        bytes memory data,\r\n        uint256 value\r\n    ) internal returns (bytes memory) {\r\n        return\r\n            functionCallWithValue(\r\n                target,\r\n                data,\r\n                value,\r\n                \"Address: low-level call with value failed\"\r\n            );\r\n    }\r\n\r\n    function functionCallWithValue(\r\n        address target,\r\n        bytes memory data,\r\n        uint256 value,\r\n        string memory errorMessage\r\n    ) internal returns (bytes memory) {\r\n        require(\r\n            address(this).balance \u003e= value,\r\n            \"Address: insufficient balance for call\"\r\n        );\r\n        return _functionCallWithValue(target, data, value, errorMessage);\r\n    }\r\n\r\n    function _functionCallWithValue(\r\n        address target,\r\n        bytes memory data,\r\n        uint256 weiValue,\r\n        string memory errorMessage\r\n    ) private returns (bytes memory) {\r\n        require(isContract(target), \"Address: call to non-contract\");\r\n\r\n        (bool success, bytes memory returndata) = target.call{value: weiValue}(\r\n            data\r\n        );\r\n        if (success) {\r\n            return returndata;\r\n        } else {\r\n            if (returndata.length \u003e 0) {\r\n                assembly {\r\n                    let returndata_size := mload(returndata)\r\n                    revert(add(32, returndata), returndata_size)\r\n                }\r\n            } else {\r\n                revert(errorMessage);\r\n            }\r\n        }\r\n    }\r\n}"},"Context.sol":{"content":"//SPDX-License-Identifier: MIT\r\npragma solidity ^0.8.0;\r\n\r\nabstract contract Context {\r\n    function _msgSender() internal view returns (address payable) {\r\n        return payable(msg.sender);\r\n    }\r\n\r\n    function _msgData() internal view returns (bytes memory) {\r\n        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\r\n        return msg.data;\r\n    }\r\n}"},"IERC20.sol":{"content":"pragma solidity ^0.8.1;\r\n// SPDX-License-Identifier: Unlicensed\r\n\r\ninterface IERC20{\r\n    /**\r\n     * @dev Emitted when `value` tokens are moved from one account (`from`) to\r\n     * another (`to`).\r\n     *\r\n     * Note that `value` may be zero.\r\n     */\r\n    event Transfer(address indexed from, address indexed to, uint256 value);\r\n\r\n    /**\r\n     * @dev Emitted when the allowance of a `spender` for an `owner` is set by\r\n     * a call to {approve}. `value` is the new allowance.\r\n     */\r\n    event Approval(address indexed owner, address indexed spender, uint256 value);\r\n\r\n    /**\r\n     * @dev Returns the amount of tokens in existence.\r\n     */\r\n    function totalSupply() external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Returns the amount of tokens owned by `account`.\r\n     */\r\n    function balanceOf(address account) external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Moves `amount` tokens from the caller\u0027s account to `to`.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transfer(address to, uint256 amount) external returns (bool);\r\n\r\n    /**\r\n     * @dev Returns the remaining number of tokens that `spender` will be\r\n     * allowed to spend on behalf of `owner` through {transferFrom}. This is\r\n     * zero by default.\r\n     *\r\n     * This value changes when {approve} or {transferFrom} are called.\r\n     */\r\n    function allowance(address owner, address spender) external view returns (uint256);\r\n\r\n    /**\r\n     * @dev Sets `amount` as the allowance of `spender` over the caller\u0027s tokens.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * IMPORTANT: Beware that changing an allowance with this method brings the risk\r\n     * that someone may use both the old and the new allowance by unfortunate\r\n     * transaction ordering. One possible solution to mitigate this race\r\n     * condition is to first reduce the spender\u0027s allowance to 0 and set the\r\n     * desired value afterwards:\r\n     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\r\n     *\r\n     * Emits an {Approval} event.\r\n     */\r\n    function approve(address spender, uint256 amount) external returns (bool);\r\n\r\n    /**\r\n     * @dev Moves `amount` tokens from `from` to `to` using the\r\n     * allowance mechanism. `amount` is then deducted from the caller\u0027s\r\n     * allowance.\r\n     *\r\n     * Returns a boolean value indicating whether the operation succeeded.\r\n     *\r\n     * Emits a {Transfer} event.\r\n     */\r\n    function transferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 amount\r\n    ) external returns (bool);\r\n}"},"IERC20MetaData.sol":{"content":"// SPDX-License-Identifier: MIT\r\npragma solidity ^0.8.0;\r\n\r\nimport \"./IERC20.sol\";\r\n\r\n/**\r\n * @dev Interface for the optional metadata functions from the ERC20 standard.\r\n *\r\n * _Available since v4.1._\r\n */\r\ninterface IERC20Metadata is IERC20 {\r\n    /**\r\n     * @dev Returns the name of the token.\r\n     */\r\n    function name() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the symbol of the token.\r\n     */\r\n    function symbol() external view returns (string memory);\r\n\r\n    /**\r\n     * @dev Returns the decimals places of the token.\r\n     */\r\n    function decimals() external view returns (uint8);\r\n}"},"IUniswapV2Factory.sol":{"content":" pragma solidity \u003e=0.5.0;\r\n// SPDX-License-Identifier: Unlicensed\r\n\r\ninterface IUniswapV2Factory {\r\n    event PairCreated(\r\n        address indexed token0,\r\n        address indexed token1,\r\n        address pair,\r\n        uint256\r\n    );\r\n\r\n    function feeTo() external view returns (address);\r\n\r\n    function feeToSetter() external view returns (address);\r\n\r\n    function getPair(address tokenA, address tokenB)\r\n        external\r\n        view\r\n        returns (address pair);\r\n\r\n    function allPairs(uint256) external view returns (address pair);\r\n\r\n    function allPairsLength() external view returns (uint256);\r\n\r\n    function createPair(address tokenA, address tokenB)\r\n        external\r\n        returns (address pair);\r\n\r\n    function setFeeTo(address) external;\r\n\r\n    function setFeeToSetter(address) external;\r\n}"},"IUniswapV2Pair.sol":{"content":"// SPDX-License-Identifier: Unlicensed\r\n pragma solidity \u003e=0.5.0;\r\n\r\ninterface IUniswapV2Pair {\r\n    event Approval(\r\n        address indexed owner,\r\n        address indexed spender,\r\n        uint256 value\r\n    );\r\n    event Transfer(address indexed from, address indexed to, uint256 value);\r\n\r\n    function name() external pure returns (string memory);\r\n\r\n    function symbol() external pure returns (string memory);\r\n\r\n    function decimals() external pure returns (uint8);\r\n\r\n    function totalSupply() external view returns (uint256);\r\n\r\n    function balanceOf(address owner) external view returns (uint256);\r\n\r\n    function allowance(address owner, address spender)\r\n        external\r\n        view\r\n        returns (uint256);\r\n\r\n    function approve(address spender, uint256 value) external returns (bool);\r\n\r\n    function transfer(address to, uint256 value) external returns (bool);\r\n\r\n    function transferFrom(\r\n        address from,\r\n        address to,\r\n        uint256 value\r\n    ) external returns (bool);\r\n\r\n    function DOMAIN_SEPARATOR() external view returns (bytes32);\r\n\r\n    function PERMIT_TYPEHASH() external pure returns (bytes32);\r\n\r\n    function nonces(address owner) external view returns (uint256);\r\n\r\n    function permit(\r\n        address owner,\r\n        address spender,\r\n        uint256 value,\r\n        uint256 deadline,\r\n        uint8 v,\r\n        bytes32 r,\r\n        bytes32 s\r\n    ) external;\r\n\r\n    event Mint(address indexed sender, uint256 amount0, uint256 amount1);\r\n    event Burn(\r\n        address indexed sender,\r\n        uint256 amount0,\r\n        uint256 amount1,\r\n        address indexed to\r\n    );\r\n    event Swap(\r\n        address indexed sender,\r\n        uint256 amount0In,\r\n        uint256 amount1In,\r\n        uint256 amount0Out,\r\n        uint256 amount1Out,\r\n        address indexed to\r\n    );\r\n    event Sync(uint112 reserve0, uint112 reserve1);\r\n\r\n    function MINIMUM_LIQUIDITY() external pure returns (uint256);\r\n\r\n    function factory() external view returns (address);\r\n\r\n    function token0() external view returns (address);\r\n\r\n    function token1() external view returns (address);\r\n\r\n    function getReserves()\r\n        external\r\n        view\r\n        returns (\r\n            uint112 reserve0,\r\n            uint112 reserve1,\r\n            uint32 blockTimestampLast\r\n        );\r\n\r\n    function price0CumulativeLast() external view returns (uint256);\r\n\r\n    function price1CumulativeLast() external view returns (uint256);\r\n\r\n    function kLast() external view returns (uint256);\r\n\r\n    function mint(address to) external returns (uint256 liquidity);\r\n\r\n    function burn(address to)\r\n        external\r\n        returns (uint256 amount0, uint256 amount1);\r\n\r\n    function swap(\r\n        uint256 amount0Out,\r\n        uint256 amount1Out,\r\n        address to,\r\n        bytes calldata data\r\n    ) external;\r\n\r\n    function skim(address to) external;\r\n\r\n    function sync() external;\r\n\r\n    function initialize(address, address) external;\r\n}"},"IUniswapV2Router01.sol":{"content":"// SPDX-License-Identifier: Unlicensed\r\npragma solidity \u003e=0.6.2;\r\n\r\ninterface IUniswapV2Router01 {\r\n    function factory() external pure returns (address);\r\n\r\n    function WETH() external pure returns (address);\r\n\r\n    function addLiquidity(\r\n        address tokenA,\r\n        address tokenB,\r\n        uint256 amountADesired,\r\n        uint256 amountBDesired,\r\n        uint256 amountAMin,\r\n        uint256 amountBMin,\r\n        address to,\r\n        uint256 deadline\r\n    )\r\n        external\r\n        returns (\r\n            uint256 amountA,\r\n            uint256 amountB,\r\n            uint256 liquidity\r\n        );\r\n\r\n    function addLiquidityETH(\r\n        address token,\r\n        uint256 amountTokenDesired,\r\n        uint256 amountTokenMin,\r\n        uint256 amountETHMin,\r\n        address to,\r\n        uint256 deadline\r\n    )\r\n        external\r\n        payable\r\n        returns (\r\n            uint256 amountToken,\r\n            uint256 amountETH,\r\n            uint256 liquidity\r\n        );\r\n\r\n    function removeLiquidity(\r\n        address tokenA,\r\n        address tokenB,\r\n        uint256 liquidity,\r\n        uint256 amountAMin,\r\n        uint256 amountBMin,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256 amountA, uint256 amountB);\r\n\r\n    function removeLiquidityETH(\r\n        address token,\r\n        uint256 liquidity,\r\n        uint256 amountTokenMin,\r\n        uint256 amountETHMin,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256 amountToken, uint256 amountETH);\r\n\r\n    function removeLiquidityWithPermit(\r\n        address tokenA,\r\n        address tokenB,\r\n        uint256 liquidity,\r\n        uint256 amountAMin,\r\n        uint256 amountBMin,\r\n        address to,\r\n        uint256 deadline,\r\n        bool approveMax,\r\n        uint8 v,\r\n        bytes32 r,\r\n        bytes32 s\r\n    ) external returns (uint256 amountA, uint256 amountB);\r\n\r\n    function removeLiquidityETHWithPermit(\r\n        address token,\r\n        uint256 liquidity,\r\n        uint256 amountTokenMin,\r\n        uint256 amountETHMin,\r\n        address to,\r\n        uint256 deadline,\r\n        bool approveMax,\r\n        uint8 v,\r\n        bytes32 r,\r\n        bytes32 s\r\n    ) external returns (uint256 amountToken, uint256 amountETH);\r\n\r\n    function swapExactTokensForTokens(\r\n        uint256 amountIn,\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256[] memory amounts);\r\n\r\n    function swapTokensForExactTokens(\r\n        uint256 amountOut,\r\n        uint256 amountInMax,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256[] memory amounts);\r\n\r\n    function swapExactETHForTokens(\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external payable returns (uint256[] memory amounts);\r\n\r\n    function swapTokensForExactETH(\r\n        uint256 amountOut,\r\n        uint256 amountInMax,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256[] memory amounts);\r\n\r\n    function swapExactTokensForETH(\r\n        uint256 amountIn,\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256[] memory amounts);\r\n\r\n    function swapETHForExactTokens(\r\n        uint256 amountOut,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external payable returns (uint256[] memory amounts);\r\n\r\n    function quote(\r\n        uint256 amountA,\r\n        uint256 reserveA,\r\n        uint256 reserveB\r\n    ) external pure returns (uint256 amountB);\r\n\r\n    function getAmountOut(\r\n        uint256 amountIn,\r\n        uint256 reserveIn,\r\n        uint256 reserveOut\r\n    ) external pure returns (uint256 amountOut);\r\n\r\n    function getAmountIn(\r\n        uint256 amountOut,\r\n        uint256 reserveIn,\r\n        uint256 reserveOut\r\n    ) external pure returns (uint256 amountIn);\r\n\r\n    function getAmountsOut(uint256 amountIn, address[] calldata path)\r\n        external\r\n        view\r\n        returns (uint256[] memory amounts);\r\n\r\n    function getAmountsIn(uint256 amountOut, address[] calldata path)\r\n        external\r\n        view\r\n        returns (uint256[] memory amounts);\r\n}"},"IUniswapV2Router02.sol":{"content":"pragma solidity \u003e=0.6.2;\r\n// SPDX-License-Identifier: Unlicensed\r\nimport \"./IUniswapV2Router01.sol\";\r\n\r\ninterface IUniswapV2Router02 is IUniswapV2Router01 {\r\n    function removeLiquidityETHSupportingFeeOnTransferTokens(\r\n        address token,\r\n        uint256 liquidity,\r\n        uint256 amountTokenMin,\r\n        uint256 amountETHMin,\r\n        address to,\r\n        uint256 deadline\r\n    ) external returns (uint256 amountETH);\r\n\r\n    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(\r\n        address token,\r\n        uint256 liquidity,\r\n        uint256 amountTokenMin,\r\n        uint256 amountETHMin,\r\n        address to,\r\n        uint256 deadline,\r\n        bool approveMax,\r\n        uint8 v,\r\n        bytes32 r,\r\n        bytes32 s\r\n    ) external returns (uint256 amountETH);\r\n\r\n    function swapExactTokensForTokensSupportingFeeOnTransferTokens(\r\n        uint256 amountIn,\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external;\r\n\r\n    function swapExactETHForTokensSupportingFeeOnTransferTokens(\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external payable;\r\n\r\n    function swapExactTokensForETHSupportingFeeOnTransferTokens(\r\n        uint256 amountIn,\r\n        uint256 amountOutMin,\r\n        address[] calldata path,\r\n        address to,\r\n        uint256 deadline\r\n    ) external;\r\n}"},"LP.sol":{"content":"pragma solidity ^0.8.1;\r\n// SPDX-License-Identifier: Unlicensed\r\nimport \"./Verifier.sol\";\r\nimport \"./IUniswapV2Factory.sol\";\r\n// made by a special little birdy \r\ncontract R is Context, Ownable, IERC20Metadata {\r\n    using Address for address;\r\n\r\n    string private _name = \"FOUR TWEETY\";\r\n    string private _symbol = \"BLAZEIT\";\r\n    uint8 private _decimals = 9;\r\n    uint256 private _tTotal = 1_000_000_000 * 10**_decimals;\r\n    address payable public _marketingWallet;\r\n\r\n    mapping(address =\u003e uint256) private _tOwned;\r\n    mapping(address =\u003e mapping(address =\u003e uint256)) private _allowances;\r\n    mapping(address =\u003e bool) public _isExcludedFromFee;\r\n    mapping(address =\u003e bool) public lpPairs;\r\n\r\n    struct IFees {\r\n        uint256 liquidityFee;\r\n        uint256 marketingFee;\r\n        uint256 totalFee;\r\n    }\r\n    IFees public BuyFees;\r\n    IFees public SellFees;\r\n    IFees public TransferFees;\r\n    IFees public MaxFees =\r\n        IFees({\r\n            liquidityFee: 50,\r\n            marketingFee: 50, \r\n            totalFee: 100\r\n        });\r\n    \r\n    struct ItxSettings {\r\n        uint256 maxTxAmount;\r\n        uint256 maxWalletAmount;\r\n        bool txLimits;\r\n    }\r\n\r\n    ItxSettings public txSettings;\r\n    uint256 constant public taxDivisor = 1000;\r\n    uint256 numTokensToSwap;\r\n    uint256 lastSwap;\r\n    uint256 swapInterval = 30 seconds;\r\n    uint256 public sellMultiplier;\r\n    uint256 sniperTaxBlocks;\r\n    uint256 constant maxSellMultiplier = 3;\r\n    uint256 public liquidityFeeAccumulator;\r\n    Verify public verifier;\r\n    IUniswapV2Router02 public immutable uniswapV2Router;\r\n    address public uniswapV2Pair;\r\n    bool inSwapAndLiquify;\r\n    bool public swapAndLiquifyEnabled;\r\n    bool public liquidityOrMarketing;\r\n    bool public tradingEnabled;\r\n    bool public feesEnabled;\r\n    modifier lockTheSwap() {\r\n        inSwapAndLiquify = true;\r\n        _;\r\n        inSwapAndLiquify = false;\r\n    }\r\n\r\n    constructor() {\r\n        setWallets(_msgSender());\r\n        setTxSettings(11,10,11,10,true);\r\n        _tOwned[_msgSender()] = _tTotal;\r\n        // IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x10ED43C718714eb63d5aA57B78B54704E256024E);\r\n        // IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x9Ac64Cc6e4415144C455BD8E4837Fea55603e5c3);\r\n        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);\r\n        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());\r\n        uniswapV2Router = _uniswapV2Router;\r\n        lpPairs[uniswapV2Pair] = true;\r\n        _approve(_msgSender(), address(_uniswapV2Router), type(uint256).max);\r\n        _approve(address(this), address(_uniswapV2Router), type(uint256).max);\r\n        verifier = new Verifier([address(this), _msgSender(), address(_uniswapV2Router), address(uniswapV2Pair)]);\r\n        _isExcludedFromFee[address(this)] = true;\r\n        _isExcludedFromFee[_msgSender()] = true;\r\n        emit Transfer(address(0), _msgSender(), _tTotal);\r\n    }\r\n\r\n    function setLpPair(address pair, bool enabled) public onlyOwner {\r\n        lpPairs[pair] = enabled;\r\n        verifier.setLpPair(pair, enabled);\r\n    }\r\n\r\n    function updateVerifier(address token, address router) public onlyOwner {\r\n        verifier.updateToken(token);\r\n        verifier.updateRouter(router);\r\n    }\r\n\r\n    //return functions\r\n\r\n    function name() external view override returns (string memory) {\r\n        return _name;\r\n    }\r\n\r\n    function symbol() external view override returns (string memory) {\r\n        return _symbol;\r\n    }\r\n\r\n    function decimals() external view override returns (uint8) {\r\n        return _decimals;\r\n    }\r\n\r\n    function totalSupply() public view override returns (uint256) {\r\n        return _tTotal;\r\n    }\r\n\r\n    function allowance(address owner, address spender) public view override returns (uint256) {\r\n        return _allowances[owner][spender];\r\n    }\r\n\r\n    function balanceOf(address account) public view override returns (uint256) {\r\n        return _tOwned[account];\r\n    }\r\n\r\n    function approve(address spender, uint256 amount) public override returns (bool) {\r\n        _approve(_msgSender(), spender, amount);\r\n        return true;\r\n    }\r\n\r\n    function getCoolDownSettings() public view returns(bool buyCooldown, bool sellCooldown, uint256 coolDownTime, uint256 coolDownLimit) {\r\n        return verifier.getCoolDownSettings();\r\n    }\r\n\r\n    function getLaunchedAt() public view returns(uint256 launchedAt){\r\n        return verifier.getLaunchedAt();\r\n    }\r\n\r\n    function getBlacklistStatus(address account) public view returns(bool) {\r\n        return verifier.getBlacklistStatus(account);\r\n    }\r\n\r\n    function limits(address from, address to) private view returns (bool) {\r\n        return from != owner()\r\n            \u0026\u0026 to != owner()\r\n            \u0026\u0026 tx.origin != owner()\r\n            \u0026\u0026 !_isExcludedFromFee[from]\r\n            \u0026\u0026 !_isExcludedFromFee[to]\r\n            \u0026\u0026 to != address(0xdead)\r\n            \u0026\u0026 to != address(0)\r\n            \u0026\u0026 from != address(this);\r\n    }\r\n\r\n    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool){\r\n        _approve(\r\n            _msgSender(),\r\n            spender,\r\n            _allowances[_msgSender()][spender] + (addedValue)\r\n        );\r\n        return true;\r\n    }\r\n\r\n    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\r\n        _approve(\r\n            _msgSender(),\r\n            spender,\r\n            _allowances[_msgSender()][spender] - (subtractedValue)\r\n        );\r\n        return true;\r\n    }\r\n\r\n    // Transaction functions\r\n    function setTxSettings(uint256 txp, uint256 txd, uint256 mwp, uint256 mwd, bool limit) public onlyOwner {\r\n        require((_tTotal * txp) / txd \u003e= _tTotal / 1000, \"Max Transaction must be above 0.1% of total supply.\");\r\n        require((_tTotal * mwp) / mwd \u003e= _tTotal / 1000, \"Max Wallet must be above 0.1% of total supply.\");\r\n        uint256 newTx = (_tTotal * txp) / txd;\r\n        uint256 newMw = (_tTotal * mwp) / mwd;\r\n        txSettings = ItxSettings ({\r\n            maxTxAmount: newTx,\r\n            maxWalletAmount: newMw,\r\n            txLimits: limit\r\n        });\r\n    }\r\n\r\n    function setCooldownEnabled(bool onoff, bool offon, uint256 amount) external onlyOwner{\r\n        verifier.setCooldownEnabled(onoff,offon);\r\n        verifier.setCooldown(amount);\r\n    }\r\n\r\n    // Tax functions\r\n\r\n    function takeFee(address sender, address receiver, uint256 amount) internal returns (uint256) {\r\n        if (_isExcludedFromFee[sender] || _isExcludedFromFee[receiver]) {return amount;}\r\n        uint256 totalFee;\r\n        if (lpPairs[receiver]) {\r\n            if(sellMultiplier \u003e= 1){\r\n                totalFee = SellFees.totalFee * sellMultiplier;\r\n            } else {\r\n                totalFee = SellFees.totalFee;\r\n            }\r\n        } else if(lpPairs[sender]){\r\n            totalFee = BuyFees.totalFee;\r\n        } else {\r\n            totalFee = TransferFees.totalFee;\r\n        }\r\n\r\n        if(block.number \u003c= getLaunchedAt() + sniperTaxBlocks){\r\n            totalFee += 500; // Adds 50% tax onto original tax;\r\n        }\r\n\r\n        uint256 feeAmount = (amount * totalFee) / taxDivisor;\r\n\r\n        _tOwned[address(this)] += feeAmount;\r\n        emit Transfer(sender, address(this), feeAmount);\r\n        liquidityFeeAccumulator += (feeAmount * (BuyFees.liquidityFee + SellFees.liquidityFee + TransferFees.liquidityFee)) / (BuyFees.totalFee + SellFees.totalFee + TransferFees.totalFee) + (BuyFees.liquidityFee + SellFees.liquidityFee + TransferFees.liquidityFee);\r\n        return amount - feeAmount;\r\n    }\r\n\r\n    function FeesEnabled(bool _enabled) public onlyOwner {\r\n        feesEnabled = _enabled;\r\n        emit areFeesEnabled(_enabled);\r\n    }\r\n\r\n    function decreaseMaxFee(uint256 _liquidityFee, uint256 _marketingFee, bool resetFees) public onlyOwner {\r\n        require(_liquidityFee \u003c= MaxFees.liquidityFee \u0026\u0026 _marketingFee \u003c= MaxFees.marketingFee);\r\n        MaxFees = IFees({\r\n            liquidityFee: _liquidityFee, \r\n            marketingFee: _marketingFee,\r\n            totalFee: _liquidityFee + _marketingFee\r\n        });\r\n        if(resetFees){\r\n            setBuyFees(_liquidityFee, _marketingFee);\r\n            setSellFees(_liquidityFee, _marketingFee);\r\n        }\r\n    }\r\n\r\n    function setBuyFees(uint256 _liquidityFee, uint256 _marketingFee) public onlyOwner {\r\n        require(_liquidityFee \u003c= MaxFees.liquidityFee \u0026\u0026 _marketingFee \u003c= MaxFees.marketingFee);\r\n        BuyFees = IFees({\r\n            liquidityFee: _liquidityFee,\r\n            marketingFee: _marketingFee,\r\n            totalFee: _liquidityFee +\r\n                _marketingFee \r\n        });\r\n    }\r\n\r\n    function setSellFees(uint256 _liquidityFee, uint256 _marketingFee) public onlyOwner {\r\n        require(_liquidityFee \u003c= MaxFees.liquidityFee \u0026\u0026 _marketingFee \u003c= MaxFees.marketingFee);\r\n        SellFees = IFees({\r\n            liquidityFee: _liquidityFee,\r\n            marketingFee: _marketingFee,\r\n            totalFee: _liquidityFee +\r\n                _marketingFee \r\n        });\r\n    }\r\n\r\n    function setTransferFees(uint256 _liquidityFee, uint256 _marketingFee) public onlyOwner {\r\n        require(_liquidityFee \u003c= MaxFees.liquidityFee \u0026\u0026 _marketingFee \u003c= MaxFees.marketingFee);\r\n        TransferFees = IFees({\r\n            liquidityFee: _liquidityFee,\r\n            marketingFee: _marketingFee,\r\n            totalFee: _liquidityFee +\r\n                _marketingFee \r\n        });\r\n    }\r\n\r\n    function excludeOrIncludeInFee(address account) public onlyOwner {\r\n        if(!_isExcludedFromFee[account]){\r\n            _isExcludedFromFee[account] = true;\r\n            verifier.feeExcluded(account);\r\n        } else {\r\n            _isExcludedFromFee[account] = false;\r\n            verifier.feeIncluded(account);\r\n        }\r\n    }\r\n\r\n    function setSellMultiplier(uint256 SM) external onlyOwner {\r\n        require(SM \u003c= maxSellMultiplier);\r\n        sellMultiplier = SM;\r\n    }\r\n\r\n    // wallet function\r\n    function setWallets(address payable m) public onlyOwner {\r\n        _marketingWallet = payable(m);\r\n    }\r\n\r\n    // blacklist\r\n    function setBlacklistStatus(address account, bool blacklisted) external onlyOwner {\r\n        verifier.setSniperStatus(account, blacklisted);\r\n    }\r\n\r\n    // contract swap functions\r\n    function setNumTokensToSwap( uint256 percent, uint256 divisor) public onlyOwner {\r\n        numTokensToSwap = (_tTotal * percent) / divisor;\r\n    }\r\n\r\n    function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner {\r\n        swapAndLiquifyEnabled = _enabled;\r\n        emit SwapAndLiquifyEnabledUpdated(_enabled);\r\n    }\r\n\r\n    //to receive ETH from uniswapV2Router when swapping\r\n    receive() external payable {}\r\n\r\n    function _approve(address owner,address spender,uint256 amount) private {\r\n        require(owner != address(0), \"ERC20: approve from the zero address\");\r\n        require(spender != address(0), \"ERC20: approve to the zero address\");\r\n\r\n        _allowances[owner][spender] = amount;\r\n        emit Approval(owner, spender, amount);\r\n    }\r\n\r\n    function clearStuckBalance(uint256 amountPercentage) external onlyOwner {\r\n        require(amountPercentage \u003c= 100);\r\n        uint256 amountETH = address(this).balance;\r\n        payable(_marketingWallet).transfer(\r\n            (amountETH * amountPercentage) / 100\r\n        );\r\n    }\r\n\r\n    function clearStuckToken(address to) external onlyOwner {\r\n        uint256 _balance = balanceOf(address(this));\r\n        _transfer(address(this), to, _balance);\r\n    }\r\n\r\n    function clearStuckTokens(address _token, address _to) external onlyOwner returns (bool _sent) {\r\n        require(_token != address(0));\r\n        uint256 _contractBalance = IERC20(_token).balanceOf(address(this));\r\n        _sent = IERC20(_token).transfer(_to, _contractBalance);\r\n    }\r\n\r\n    function airDropTokens(address[] memory addresses, uint256[] memory amounts) external {\r\n        require(addresses.length == amounts.length, \"Lengths do not match.\");\r\n        for (uint8 i = 0; i \u003c addresses.length; i++) {\r\n            require(balanceOf(_msgSender()) \u003e= amounts[i]);\r\n            _transfer(_msgSender(), addresses[i], amounts[i]*10**_decimals);\r\n        }\r\n    }\r\n\r\n    function swapAndLiquify() private lockTheSwap {\r\n        if(liquidityOrMarketing \u0026\u0026 liquidityFeeAccumulator \u003e= numTokensToSwap){\r\n            uint256 liquidityTokens = numTokensToSwap / 2;\r\n            swapTokensForEth(numTokensToSwap - liquidityTokens);\r\n            uint256 toLiquidity = address(this).balance;\r\n            addLiquidity(liquidityTokens, toLiquidity);\r\n            emit SwapAndLiquify(liquidityTokens, toLiquidity);\r\n            liquidityFeeAccumulator -= numTokensToSwap;\r\n            if(liquidityFeeAccumulator \u003c= numTokensToSwap) {\r\n                liquidityOrMarketing = false;\r\n            }\r\n        } else {\r\n            swapTokensForEth(numTokensToSwap);\r\n            uint256 toMarketing = address(this).balance;\r\n            _marketingWallet.transfer(toMarketing);\r\n            emit ToMarketing(toMarketing);\r\n            if(!liquidityOrMarketing \u0026\u0026 liquidityFeeAccumulator \u003e= numTokensToSwap){\r\n                liquidityOrMarketing = true;\r\n            }\r\n        }\r\n    }\r\n\r\n    function swapTokensForEth(uint256 tokenAmount) private {\r\n        // generate the uniswap pair path of token -\u003e weth\r\n        address[] memory path = new address[](2);\r\n        path[0] = address(this);\r\n        path[1] = uniswapV2Router.WETH();\r\n\r\n        if(_allowances[address(this)][address(uniswapV2Router)] != type(uint256).max) {\r\n            _allowances[address(this)][address(uniswapV2Router)] = type(uint256).max;\r\n        }\r\n        // make the swap\r\n        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(\r\n            tokenAmount,\r\n            0, // accept any amount of ETH\r\n            path,\r\n            address(this),\r\n            block.timestamp\r\n        );\r\n    }\r\n\r\n    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {\r\n        // approve token transfer to cover all possible scenarios\r\n        if(_allowances[address(this)][address(uniswapV2Router)] != type(uint256).max) {\r\n            _allowances[address(this)][address(uniswapV2Router)] = type(uint256).max;\r\n        }\r\n        // add the liquidity\r\n        uniswapV2Router.addLiquidityETH{value: ethAmount}(\r\n            address(this),\r\n            tokenAmount,\r\n            0, // slippage is unavoidable\r\n            0, // slippage is unavoidable\r\n            owner(),\r\n            block.timestamp\r\n        );\r\n    }\r\n\r\n    function transferFrom(address sender,address recipient,uint256 amount) public override returns (bool) {\r\n        _transfer(sender, recipient, amount);\r\n        _approve(\r\n            sender,\r\n            _msgSender(),\r\n            _allowances[sender][_msgSender()] - (\r\n                amount\r\n            )\r\n        );\r\n        return true;\r\n    }\r\n\r\n    function setLaunch() internal {\r\n        setSellFees(50,50);\r\n        setBuyFees(50,50);\r\n        FeesEnabled(true);\r\n        setTransferFees(5,5);\r\n        setNumTokensToSwap(1,1000);\r\n        setSwapAndLiquifyEnabled(true);\r\n        setTxSettings(1,100,2,100,true);\r\n    }\r\n    \r\n    function checkLaunch(uint256 blockAmount) internal {\r\n        verifier.checkLaunch(block.number, true, true, blockAmount);\r\n    }\r\n\r\n    function enableTrading(uint256 blockAmount) public onlyOwner {\r\n        require(blockAmount \u003c= 5);\r\n        require(!tradingEnabled);\r\n        setLaunch();\r\n        sniperTaxBlocks = blockAmount;\r\n        checkLaunch(blockAmount);\r\n        enableTrading();\r\n        emit Launch();\r\n    }\r\n    \r\n    function enableTrading() private {\r\n        tradingEnabled = true;\r\n    }\r\n\r\n    function _basicTransfer(address from, address to, uint256 amount) internal returns (bool) {\r\n        _tOwned[from] -= amount;\r\n        _tOwned[to] += amount;\r\n        emit Transfer(from, to, amount);\r\n        return true;\r\n    }\r\n\r\n    function _transfer(address from, address to, uint256 amount) private returns(bool){\r\n        require(from != address(0), \"ERC20: transfer from the zero address\");\r\n        require(to != address(0), \"ERC20: transfer to the zero address\");\r\n        require(amount \u003e 0, \"Transfer amount must be greater than zero\");\r\n        if(inSwapAndLiquify){\r\n           return _basicTransfer(from, to, amount);\r\n        }\r\n        if(limits(from, to)){\r\n            if(!tradingEnabled) {\r\n                revert();\r\n            }\r\n            if(tradingEnabled){\r\n                if (txSettings.txLimits) {\r\n                    if (lpPairs[from] || lpPairs[to]) {\r\n                        if(!_isExcludedFromFee[to] \u0026\u0026 !_isExcludedFromFee[from]) {\r\n                            require(amount \u003c= txSettings.maxTxAmount);\r\n                        }\r\n                    }\r\n\r\n                    if(to != address(uniswapV2Router) \u0026\u0026 !lpPairs[to]) {\r\n                        if(!_isExcludedFromFee[to]){\r\n                            require(balanceOf(to) + amount \u003c= txSettings.maxWalletAmount);\r\n                        }\r\n                    }\r\n\r\n                    if (lpPairs[to]){\r\n                        if(swapAndLiquifyEnabled \u0026\u0026 !inSwapAndLiquify){\r\n                            if(lastSwap + swapInterval \u003c= block.timestamp){\r\n                                if(balanceOf(address(this)) \u003e numTokensToSwap) {\r\n                                    swapAndLiquify();        \r\n                                    lastSwap = block.timestamp;\r\n                                }\r\n                            }\r\n                        }\r\n                    }\r\n                }\r\n            }\r\n        }        \r\n        return _transferCheck(from, to, amount);\r\n    }\r\n\r\n    function _transferCheck(address from, address to, uint256 amount) private returns(bool){\r\n        if(tradingEnabled){\r\n            if(limits(from, to)) {\r\n                verifier.verifyUser(from, to);\r\n            }\r\n        }\r\n        _tOwned[from] -= amount;\r\n        uint256 amountSent = feesEnabled \u0026\u0026 !_isExcludedFromFee[from] ? takeFee(from, to, amount) : amount;\r\n        _tOwned[to] += amountSent;\r\n        emit Transfer(from, to, amountSent);\r\n        return true;\r\n    }\r\n\r\n    function transfer(address recipient, uint256 amount) public override returns (bool) {\r\n        _transfer(_msgSender(), recipient, amount);\r\n        return true;\r\n    }\r\n\r\n    event ToMarketing(uint256 marketingBalance);\r\n    event SwapAndLiquify(uint256 liquidityTokens, uint256 liquidityFees);    \r\n    event Launch();\r\n    event SwapAndLiquifyEnabledUpdated(bool enabled);\r\n    event areFeesEnabled(bool _enabled);\r\n\r\n}"},"Ownable.sol":{"content":"pragma solidity ^0.8.1;\r\n// SPDX-License-Identifier: Unlicensed\r\nimport \"./Context.sol\";\r\ncontract Ownable is Context {\r\n    address private _owner;\r\n    address private _previousOwner;\r\n    uint256 private _lockTime;\r\n\r\n    event OwnershipTransferred(\r\n        address indexed previousOwner,\r\n        address indexed newOwner\r\n    );\r\n\r\n    constructor() {\r\n        address msgSender = _msgSender();\r\n        _owner = msgSender;\r\n        emit OwnershipTransferred(address(0), msgSender);\r\n    }\r\n\r\n    function owner() public view returns (address) {\r\n        return _owner;\r\n    }\r\n\r\n    modifier onlyOwner() {\r\n        require(_owner == _msgSender(), \"Ownable: caller is not the owner\");\r\n        _;\r\n    }\r\n\r\n    function renounceOwnership() public virtual onlyOwner {\r\n        emit OwnershipTransferred(_owner, address(0));\r\n        _owner = address(0);\r\n    }\r\n\r\n    function transferOwnership(address newOwner) public virtual onlyOwner {\r\n        require(\r\n            newOwner != address(0),\r\n            \"Ownable: new owner is the zero address\"\r\n        );\r\n        emit OwnershipTransferred(_owner, newOwner);\r\n        _owner = newOwner;\r\n    }\r\n}"},"Verifier.sol":{"content":"pragma solidity ^0.8.1;\r\n// SPDX-License-Identifier: Unlicensed\r\nimport \"./IERC20MetaData.sol\";\r\nimport \"./Verify.sol\";\r\nimport \"./Ownable.sol\";\r\nimport \"./IUniswapV2Pair.sol\";\r\nimport \"./IUniswapV2Router02.sol\";\r\nimport \"./Address.sol\";\r\n\r\ncontract Verifier is Verify{\r\n    using Address for address;\r\n    mapping (address =\u003e bool) lpPairs;\r\n    mapping(address =\u003e uint256) private buycooldown;\r\n    mapping(address =\u003e uint256) private sellcooldown;\r\n    mapping(address =\u003e bool) public _isBlacklisted;\r\n    mapping(address =\u003e bool) public _isExcludedFromFee;\r\n    address _token;\r\n    IUniswapV2Router02 public uniswapV2Router;\r\n    modifier onlyToken() {\r\n        require(msg.sender == _token); _;\r\n    }\r\n    struct ILaunch {\r\n        uint256 launchedAt;\r\n        uint256 antiBlocks;\r\n        bool launched;\r\n        bool launchProtection;\r\n    }\r\n    ILaunch public wenLaunch;\r\n\r\n    struct Icooldown {\r\n        bool buycooldownEnabled;\r\n        bool sellcooldownEnabled;\r\n        uint256 cooldown;\r\n        uint256 cooldownLimit;\r\n    }\r\n    Icooldown public cooldownInfo =\r\n        Icooldown({\r\n            buycooldownEnabled: true,\r\n            sellcooldownEnabled: true,\r\n            cooldown: 30 seconds,\r\n            cooldownLimit: 60 seconds\r\n        });\r\n\r\n\r\n    constructor(address[4] memory addresses) {\r\n        uniswapV2Router = IUniswapV2Router02(addresses[2]);\r\n        _token = addresses[0];\r\n        _isExcludedFromFee[addresses[0]] = true;\r\n        _isExcludedFromFee[addresses[1]] = true;\r\n        lpPairs[addresses[3]] = true;\r\n    }\r\n    \r\n    function updateToken(address token) external override onlyToken {\r\n        _token = token;\r\n    }\r\n\r\n    function updateRouter(address router) external override onlyToken {\r\n        uniswapV2Router = IUniswapV2Router02(router);\r\n    }\r\n\r\n    function feeExcluded(address account) external override onlyToken {\r\n        _isExcludedFromFee[account] = true;\r\n    }\r\n\r\n    function feeIncluded(address account) external override onlyToken {\r\n        _isExcludedFromFee[account] = false;\r\n    }\r\n\r\n    function getCoolDownSettings() public view override returns(bool, bool, uint256, uint256) {\r\n        return(cooldownInfo.buycooldownEnabled, cooldownInfo.sellcooldownEnabled, cooldownInfo.cooldown, cooldownInfo.cooldownLimit);\r\n    }\r\n        \r\n    function getBlacklistStatus(address account) external view override returns(bool) {\r\n        return _isBlacklisted[account];\r\n    }\r\n\r\n    function setCooldownEnabled(bool onoff, bool offon) external override onlyToken {\r\n        cooldownInfo.buycooldownEnabled = onoff;\r\n        cooldownInfo.sellcooldownEnabled = offon;\r\n    }\r\n\r\n    function setCooldown(uint256 amount) external override onlyToken {\r\n        require(amount \u003c= cooldownInfo.cooldownLimit);\r\n        cooldownInfo.cooldown = amount;\r\n    }\r\n\r\n    function setSniperStatus(address account, bool blacklisted) external override onlyToken {\r\n        _setSniperStatus(account, blacklisted);\r\n    }\r\n\r\n    function _setSniperStatus(address account, bool blacklisted) internal {\r\n        if(lpPairs[account] || account == address(_token) || account == address(uniswapV2Router) || _isExcludedFromFee[account]) {revert();}\r\n        \r\n        if (blacklisted == true) {\r\n            _isBlacklisted[account] = true;\r\n        } else {\r\n            _isBlacklisted[account] = false;\r\n        }    \r\n    }\r\n\r\n    function getLaunchedAt() external override view returns(uint256 launchedAt){\r\n        return wenLaunch.launchedAt;\r\n    }\r\n\r\n    function checkLaunch(uint256 launchedAt, bool launched, bool protection, uint256 blockAmount) external override onlyToken {\r\n        wenLaunch.launchedAt = launchedAt;\r\n        wenLaunch.launched = launched;\r\n        wenLaunch.launchProtection = protection;\r\n        wenLaunch.antiBlocks = blockAmount;\r\n    }\r\n\r\n    function setLpPair(address pair, bool enabled) external override onlyToken {\r\n        lpPairs[pair] = enabled;\r\n    }\r\n\r\n    function verifyUser(address from, address to) public override onlyToken {\r\n        require(!_isBlacklisted[to]);\r\n        require(!_isBlacklisted[from]);\r\n        if (wenLaunch.launchProtection) {\r\n            if (lpPairs[from] \u0026\u0026 to != address(uniswapV2Router) \u0026\u0026 !_isExcludedFromFee[to]) {\r\n                if (block.number \u003c= wenLaunch.launchedAt + wenLaunch.antiBlocks) {\r\n                    _setSniperStatus(to, true);\r\n              }\r\n            } else {\r\n                wenLaunch.launchProtection = false;\r\n            }\r\n        }\r\n        if (lpPairs[from] \u0026\u0026 to != address(uniswapV2Router) \u0026\u0026 !_isExcludedFromFee[to] \u0026\u0026 cooldownInfo.buycooldownEnabled) {\r\n            require(buycooldown[to] \u003c block.timestamp);\r\n            buycooldown[to] = block.timestamp + (cooldownInfo.cooldown);\r\n            } else if (!lpPairs[from] \u0026\u0026 !_isExcludedFromFee[from] \u0026\u0026 cooldownInfo.sellcooldownEnabled){\r\n                require(sellcooldown[from] \u003c= block.timestamp);\r\n                sellcooldown[from] = block.timestamp + (cooldownInfo.cooldown);\r\n            } \r\n    }\r\n}"},"Verify.sol":{"content":"pragma solidity ^0.8.1;\r\n// SPDX-License-Identifier: Unlicensed\r\ninterface Verify {\r\n    function setSniperStatus(address account, bool blacklisted) external;\r\n    function setLpPair(address pair, bool enabled) external;\r\n    function verifyUser(address from, address to) external;\r\n    function checkLaunch(uint256 launchedAt, bool launched, bool protection, uint256 blockAmount) external;\r\n    function feeExcluded(address account) external;\r\n    function feeIncluded(address account) external;\r\n    function getCoolDownSettings() external view returns(bool buyCooldown, bool sellCooldown, uint256 coolDownTime, uint256 coolDownLimit);\r\n    function getBlacklistStatus(address account) external view returns(bool);\r\n    function setCooldownEnabled(bool onoff, bool offon) external;\r\n    function setCooldown(uint256 amount) external;\r\n    function updateToken(address token) external;\r\n    function updateRouter(address router) external;\r\n    function getLaunchedAt() external view returns(uint256 launchedAt);\r\n}"}}

pragma solidity =0.5.16;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

contract UniswapV2Factory is IUniswapV2Factory {
    address public feeTo;
    address public feeToSetter;

    mapping(address => mapping(address => address)) public getPair;
    address[] public allPairs;

    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    constructor(address _feeToSetter) public {
        feeToSetter = _feeToSetter;
    }

    function allPairsLength() external view returns (uint) {
        return allPairs.length;
    }

    function createPair(address tokenA, address tokenB) external returns (address pair) {
        require(tokenA != tokenB, 'UniswapV2: IDENTICAL_ADDRESSES');
        (address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2: ZERO_ADDRESS');
        require(getPair[token0][token1] == address(0), 'UniswapV2: PAIR_EXISTS'); // single check is sufficient
        bytes memory bytecode = type(UniswapV2Pair).creationCode;
        bytes32 salt = keccak256(abi.encodePacked(token0, token1));
        assembly {
            pair := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        IUniswapV2Pair(pair).initialize(token0, token1);
        getPair[token0][token1] = pair;
        getPair[token1][token0] = pair; // populate mapping in the reverse direction
        allPairs.push(pair);
        emit PairCreated(token0, token1, pair, allPairs.length);
    }

    function setFeeTo(address _feeTo) external {
        require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
        feeTo = _feeTo;
    }

    function setFeeToSetter(address _feeToSetter) external {
        require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
        feeToSetter = _feeToSetter;
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}