// Sources flattened with hardhat v2.5.0 https://hardhat.org

// File @openzeppelin/contracts/token/ERC20/[email protected]

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}


// File @openzeppelin/contracts/token/ERC20/extensions/[email protected]


pragma solidity ^0.8.0;

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}


// File @openzeppelin/contracts/utils/[email protected]


pragma solidity ^0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}


// File @openzeppelin/contracts/token/ERC20/[email protected]


pragma solidity ^0.8.0;



/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}


// File @openzeppelin/contracts/access/[email protected]


pragma solidity ^0.8.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _setOwner(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _setOwner(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}


// File @openzeppelin/contracts/utils/math/[email protected]


pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}


// File contracts/StripToken.sol


/******************************************************************************
           ██                                                                
   ▒▓▓▒    ██     ▒▒                                                         
  ██████   ██ ▒▓█▓   ████  ██████ █████   █  ████     ███   ████   █  █    ██  
  ██████▒  ▓███▒    █▒▒▒█▒  ▒██▒▒ ██▒▒▒█  █▒ █▒▒██   █▒ ▒█  █▒▒██  █▒ ██▒  ██▒ 
   ▓██▓▒▒▓███▒      ██       ██▒  ██▒  █     █▒  █  ██▒    ██▒  █▒    ███▒ ██▒ 
      ▒██████       ▒████▒   ██▒  █████▒  █▒ ████▒  ██▒    ██▒  █▒ █▒ ██▒█▒██▒ 
    ▓█████ ▓█         ▒▒██▒  ██▒  ██▒▒██  █▒ ██▒    ██▒    ██▒  █▒ █▒ ██▒▒███▒ 
   ███████ ██      ▒█   ██▒  ██▒  ██▒  █▒ █▒ ██▒    ▒██  █ ██▒ ██▒ █▒ ██▒ ▒██▒ 
   ████████▓▓       █████▒   ██▒  ██▒  ██▒█▒ ██▒     ▒███▒  ████▒  █▒ ██▒  ▒█▒ 
    ▒███████████▓▒▒                                                          
       ▒▓█████████████▒    ===================================================
           ▓▓███████████▓       
           ██  ▒█████████▒      
           ██    ████████       Token..: STRIPCOIN
           ██  ▒███████▒        Version: 1.0
           ██▒██████▒           License: MIT
           ██████▒              
         ▒████▒                 
       ▓█████                   
    ▒▓█▓▒  ▓█                   
  ▒█▓▒     ██                   
▒▓▒        ██      
*******************************************************************************/             

pragma solidity ^0.8.0;




/**
 * @title StripToken Contract
 * @author 
 * @dev
 */

contract StripToken is ERC20, Ownable {
    using SafeMath for uint256;

    // modify token name
    string public constant NAME = 'StripCoin';
    // modify token symbol
    string public constant SYMBOL = 'STRIP';
    // modify token decimals
    uint8 public constant DECIMALS = 18;
    // modify initial token supply
    uint256 public constant TOTAL_SUPPLY = 500e9 * (10**uint256(DECIMALS)); // 500,000,000,000 tokens
    // multisig contract address
    address public multiSigAdmin;

    event MultiSigAdminUpdated(address _multiSigAdmin);

    /**
     * @dev Constructor that gives msg.sender all of existing tokens.
     */
    constructor() Ownable() ERC20(NAME, SYMBOL) {
        _mint(msg.sender, TOTAL_SUPPLY);
    }

    /**
     * @dev Override decimals() function to customize decimals
     */
    function decimals() public view virtual override returns (uint8) {
        return DECIMALS;
    }

    function setMultiSigAdminAddress(address _multiSigAdmin) external onlyOwner {
        require (_multiSigAdmin != address(0x00), "Invalid MultiSig admin address");
        multiSigAdmin = _multiSigAdmin;
        emit MultiSigAdminUpdated(multiSigAdmin);
    }
    
    /**
     * @dev Recovers the ERC20 token balance mistakenly sent to the contract. Only multisig contract can call this function
     * @param tokenAddress The token contract address
     * @param tokenAmount Number of tokens to be sent
     */
    function recoverERC20(address tokenAddress, uint256 tokenAmount) external onlyMultiSigAdmin {
        IERC20(tokenAddress).transfer(owner(), tokenAmount);
    }

    // modifier for multiSig only
    modifier onlyMultiSigAdmin() {
        require(msg.sender == multiSigAdmin, "Should be multiSig contract");
        _;
    }
}

// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.4;
import {Clone} from "Clone.sol";
import {ERC20} from "ERC20.sol";
import {SafeTransferLib} from "SafeTransferLib.sol";
import {Ownable} from "Ownable.sol";
import {FullMath} from "FullMath.sol";
/// @title ERC20StakingPool
/// @author zefram.eth
/// @notice A modern, gas optimized staking pool contract for rewarding ERC20 stakers
/// with ERC20 tokens periodically and continuously
contract ERC20StakingPool is Ownable, Clone {
    /// -----------------------------------------------------------------------
    /// Library usage
    /// -----------------------------------------------------------------------
    using SafeTransferLib for ERC20;
    /// -----------------------------------------------------------------------
    /// Errors
    /// -----------------------------------------------------------------------
    error Error_ZeroOwner();
    error Error_AlreadyInitialized();
    error Error_NotRewardDistributor();
    error Error_AmountTooLarge();
    /// -----------------------------------------------------------------------
    /// Events
    /// -----------------------------------------------------------------------
    event RewardAdded(uint256 reward);
    event Staked(address indexed user, uint256 amount);
    event Withdrawn(address indexed user, uint256 amount);
    event RewardPaid(address indexed user, uint256 reward);
    /// -----------------------------------------------------------------------
    /// Constants
    /// -----------------------------------------------------------------------
    uint256 internal constant PRECISION = 1e30;
    /// -----------------------------------------------------------------------
    /// Storage variables
    /// -----------------------------------------------------------------------
    /// @notice The last Unix timestamp (in seconds) when rewardPerTokenStored was updated
    uint64 public lastUpdateTime;
    /// @notice The Unix timestamp (in seconds) at which the current reward period ends
    uint64 public periodFinish;
    /// @notice The per-second rate at which rewardPerToken increases
    uint256 public rewardRate;
    /// @notice The last stored rewardPerToken value
    uint256 public rewardPerTokenStored;
    /// @notice The total tokens staked in the pool
    uint256 public totalSupply;
    /// @notice Tracks if an address can call notifyReward()
    mapping(address => bool) public isRewardDistributor;
    /// @notice The amount of tokens staked by an account
    mapping(address => uint256) public balanceOf;
    /// @notice The rewardPerToken value when an account last staked/withdrew/withdrew rewards
    mapping(address => uint256) public userRewardPerTokenPaid;
    /// @notice The earned() value when an account last staked/withdrew/withdrew rewards
    mapping(address => uint256) public rewards;
    /// -----------------------------------------------------------------------
    /// Immutable parameters
    /// -----------------------------------------------------------------------
    /// @notice The token being rewarded to stakers
    function rewardToken() public pure returns (ERC20 rewardToken_) {
        return ERC20(_getArgAddress(0));
    }
    /// @notice The token being staked in the pool
    function stakeToken() public pure returns (ERC20 stakeToken_) {
        return ERC20(_getArgAddress(0x14));
    }
    /// @notice The length of each reward period, in seconds
    function DURATION() public pure returns (uint64 DURATION_) {
        return _getArgUint64(0x28);
    }
    /// -----------------------------------------------------------------------
    /// Initialization
    /// -----------------------------------------------------------------------
    /// @notice Initializes the owner, called by StakingPoolFactory
    /// @param initialOwner The initial owner of the contract
    function initialize(address initialOwner) external {
        if (owner() != address(0)) {
            revert Error_AlreadyInitialized();
        }
        if (initialOwner == address(0)) {
            revert Error_ZeroOwner();
        }
        _transferOwnership(initialOwner);
    }
    /// -----------------------------------------------------------------------
    /// User actions
    /// -----------------------------------------------------------------------
    /// @notice Stakes tokens in the pool to earn rewards
    /// @param amount The amount of tokens to stake
    function stake(uint256 amount) external {
        /// -----------------------------------------------------------------------
        /// Validation
        /// -----------------------------------------------------------------------
        if (amount == 0) {
            return;
        }
        /// -----------------------------------------------------------------------
        /// Storage loads
        /// -----------------------------------------------------------------------
        uint256 accountBalance = balanceOf[msg.sender];
        uint64 lastTimeRewardApplicable_ = lastTimeRewardApplicable();
        uint256 totalSupply_ = totalSupply;
        uint256 rewardPerToken_ = _rewardPerToken(
            totalSupply_,
            lastTimeRewardApplicable_,
            rewardRate
        );
        /// -----------------------------------------------------------------------
        /// State updates
        /// -----------------------------------------------------------------------
        // accrue rewards
        rewardPerTokenStored = rewardPerToken_;
        lastUpdateTime = lastTimeRewardApplicable_;
        rewards[msg.sender] = _earned(
            msg.sender,
            accountBalance,
            rewardPerToken_,
            rewards[msg.sender]
        );
        userRewardPerTokenPaid[msg.sender] = rewardPerToken_;
        // stake
        totalSupply = totalSupply_ + amount;
        balanceOf[msg.sender] = accountBalance + amount;
        /// -----------------------------------------------------------------------
        /// Effects
        /// -----------------------------------------------------------------------
        stakeToken().safeTransferFrom(msg.sender, address(this), amount);
        emit Staked(msg.sender, amount);
    }
    /// @notice Withdraws staked tokens from the pool
    /// @param amount The amount of tokens to withdraw
    function withdraw(uint256 amount) external {
        /// -----------------------------------------------------------------------
        /// Validation
        /// -----------------------------------------------------------------------
        if (amount == 0) {
            return;
        }
        /// -----------------------------------------------------------------------
        /// Storage loads
        /// -----------------------------------------------------------------------
        uint256 accountBalance = balanceOf[msg.sender];
        uint64 lastTimeRewardApplicable_ = lastTimeRewardApplicable();
        uint256 totalSupply_ = totalSupply;
        uint256 rewardPerToken_ = _rewardPerToken(
            totalSupply_,
            lastTimeRewardApplicable_,
            rewardRate
        );
        /// -----------------------------------------------------------------------
        /// State updates
        /// -----------------------------------------------------------------------
        // accrue rewards
        rewardPerTokenStored = rewardPerToken_;
        lastUpdateTime = lastTimeRewardApplicable_;
        rewards[msg.sender] = _earned(
            msg.sender,
            accountBalance,
            rewardPerToken_,
            rewards[msg.sender]
        );
        userRewardPerTokenPaid[msg.sender] = rewardPerToken_;
        // withdraw stake
        balanceOf[msg.sender] = accountBalance - amount;
        // total supply has 1:1 relationship with staked amounts
        // so can't ever underflow
        unchecked {
            totalSupply = totalSupply_ - amount;
        }
        /// -----------------------------------------------------------------------
        /// Effects
        /// -----------------------------------------------------------------------
        stakeToken().safeTransfer(msg.sender, amount);
        emit Withdrawn(msg.sender, amount);
    }
    /// @notice Withdraws all staked tokens and earned rewards
    function exit() external {
        /// -----------------------------------------------------------------------
        /// Validation
        /// -----------------------------------------------------------------------
        uint256 accountBalance = balanceOf[msg.sender];
        /// -----------------------------------------------------------------------
        /// Storage loads
        /// -----------------------------------------------------------------------
        uint64 lastTimeRewardApplicable_ = lastTimeRewardApplicable();
        uint256 totalSupply_ = totalSupply;
        uint256 rewardPerToken_ = _rewardPerToken(
            totalSupply_,
            lastTimeRewardApplicable_,
            rewardRate
        );
        /// -----------------------------------------------------------------------
        /// State updates
        /// -----------------------------------------------------------------------
        // give rewards
        uint256 reward = _earned(
            msg.sender,
            accountBalance,
            rewardPerToken_,
            rewards[msg.sender]
        );
        if (reward > 0) {
            rewards[msg.sender] = 0;
        }
        // accrue rewards
        rewardPerTokenStored = rewardPerToken_;
        lastUpdateTime = lastTimeRewardApplicable_;
        userRewardPerTokenPaid[msg.sender] = rewardPerToken_;
        // withdraw stake
        balanceOf[msg.sender] = 0;
        // total supply has 1:1 relationship with staked amounts
        // so can't ever underflow
        unchecked {
            totalSupply = totalSupply_ - accountBalance;
        }
        /// -----------------------------------------------------------------------
        /// Effects
        /// -----------------------------------------------------------------------
        // transfer stake
        stakeToken().safeTransfer(msg.sender, accountBalance);
        emit Withdrawn(msg.sender, accountBalance);
        // transfer rewards
        if (reward > 0) {
            rewardToken().safeTransfer(msg.sender, reward);
            emit RewardPaid(msg.sender, reward);
        }
    }
    /// @notice Withdraws all earned rewards
    function getReward() external {
        /// -----------------------------------------------------------------------
        /// Storage loads
        /// -----------------------------------------------------------------------
        uint256 accountBalance = balanceOf[msg.sender];
        uint64 lastTimeRewardApplicable_ = lastTimeRewardApplicable();
        uint256 totalSupply_ = totalSupply;
        uint256 rewardPerToken_ = _rewardPerToken(
            totalSupply_,
            lastTimeRewardApplicable_,
            rewardRate
        );
        /// -----------------------------------------------------------------------
        /// State updates
        /// -----------------------------------------------------------------------
        uint256 reward = _earned(
            msg.sender,
            accountBalance,
            rewardPerToken_,
            rewards[msg.sender]
        );
        // accrue rewards
        rewardPerTokenStored = rewardPerToken_;
        lastUpdateTime = lastTimeRewardApplicable_;
        userRewardPerTokenPaid[msg.sender] = rewardPerToken_;
        // withdraw rewards
        if (reward > 0) {
            rewards[msg.sender] = 0;
            /// -----------------------------------------------------------------------
            /// Effects
            /// -----------------------------------------------------------------------
            rewardToken().safeTransfer(msg.sender, reward);
            emit RewardPaid(msg.sender, reward);
        }
    }
    /// -----------------------------------------------------------------------
    /// Getters
    /// -----------------------------------------------------------------------
    /// @notice The latest time at which stakers are earning rewards.
    function lastTimeRewardApplicable() public view returns (uint64) {
        return
            block.timestamp < periodFinish
                ? uint64(block.timestamp)
                : periodFinish;
    }
    /// @notice The amount of reward tokens each staked token has earned so far
    function rewardPerToken() external view returns (uint256) {
        return
            _rewardPerToken(
                totalSupply,
                lastTimeRewardApplicable(),
                rewardRate
            );
    }
    /// @notice The amount of reward tokens an account has accrued so far. Does not
    /// include already withdrawn rewards.
    function earned(address account) external view returns (uint256) {
        return
            _earned(
                account,
                balanceOf[account],
                _rewardPerToken(
                    totalSupply,
                    lastTimeRewardApplicable(),
                    rewardRate
                ),
                rewards[account]
            );
    }
    /// -----------------------------------------------------------------------
    /// Owner actions
    /// -----------------------------------------------------------------------
    /// @notice Lets a reward distributor start a new reward period. The reward tokens must have already
    /// been transferred to this contract before calling this function. If it is called
    /// when a reward period is still active, a new reward period will begin from the time
    /// of calling this function, using the leftover rewards from the old reward period plus
    /// the newly sent rewards as the reward.
    /// @dev If the reward amount will cause an overflow when computing rewardPerToken, then
    /// this function will revert.
    /// @param reward The amount of reward tokens to use in the new reward period.
    function notifyRewardAmount(uint256 reward) external {
        /// -----------------------------------------------------------------------
        /// Validation
        /// -----------------------------------------------------------------------
        if (reward == 0) {
            return;
        }
        if (!isRewardDistributor[msg.sender]) {
            revert Error_NotRewardDistributor();
        }
        /// -----------------------------------------------------------------------
        /// Storage loads
        /// -----------------------------------------------------------------------
        uint256 rewardRate_ = rewardRate;
        uint64 periodFinish_ = periodFinish;
        uint64 lastTimeRewardApplicable_ = block.timestamp < periodFinish_
            ? uint64(block.timestamp)
            : periodFinish_;
        uint64 DURATION_ = DURATION();
        uint256 totalSupply_ = totalSupply;
        /// -----------------------------------------------------------------------
        /// State updates
        /// -----------------------------------------------------------------------
        // accrue rewards
        rewardPerTokenStored = _rewardPerToken(
            totalSupply_,
            lastTimeRewardApplicable_,
            rewardRate_
        );
        lastUpdateTime = lastTimeRewardApplicable_;
        // record new reward
        uint256 newRewardRate;
        if (block.timestamp >= periodFinish_) {
            newRewardRate = reward / DURATION_;
        } else {
            uint256 remaining = periodFinish_ - block.timestamp;
            uint256 leftover = remaining * rewardRate_;
            newRewardRate = (reward + leftover) / DURATION_;
        }
        // prevent overflow when computing rewardPerToken
        if (newRewardRate >= ((type(uint256).max / PRECISION) / DURATION_)) {
            revert Error_AmountTooLarge();
        }
        rewardRate = newRewardRate;
        lastUpdateTime = uint64(block.timestamp);
        periodFinish = uint64(block.timestamp + DURATION_);
        emit RewardAdded(reward);
    }
    /// @notice Lets the owner add/remove accounts from the list of reward distributors.
    /// Reward distributors can call notifyRewardAmount()
    /// @param rewardDistributor The account to add/remove
    /// @param isRewardDistributor_ True to add the account, false to remove the account
    function setRewardDistributor(
        address rewardDistributor,
        bool isRewardDistributor_
    ) external onlyOwner {
        isRewardDistributor[rewardDistributor] = isRewardDistributor_;
    }
    /// -----------------------------------------------------------------------
    /// Internal functions
    /// -----------------------------------------------------------------------
    function _earned(
        address account,
        uint256 accountBalance,
        uint256 rewardPerToken_,
        uint256 accountRewards
    ) internal view returns (uint256) {
        return
            FullMath.mulDiv(
                accountBalance,
                rewardPerToken_ - userRewardPerTokenPaid[account],
                PRECISION
            ) + accountRewards;
    }
    function _rewardPerToken(
        uint256 totalSupply_,
        uint256 lastTimeRewardApplicable_,
        uint256 rewardRate_
    ) internal view returns (uint256) {
        if (totalSupply_ == 0) {
            return rewardPerTokenStored;
        }
        return
            rewardPerTokenStored +
            FullMath.mulDiv(
                (lastTimeRewardApplicable_ - lastUpdateTime) * PRECISION,
                rewardRate_,
                totalSupply_
            );
    }
    function _getImmutableVariablesOffset()
        internal
        pure
        returns (uint256 offset)
    {
        assembly {
            offset := sub(
                calldatasize(),
                add(shr(240, calldataload(sub(calldatasize(), 2))), 2)
            )
        }
    }
}
// SPDX-License-Identifier: BSD
pragma solidity ^0.8.4;
/// @title Clone
/// @author zefram.eth
/// @notice Provides helper functions for reading immutable args from calldata
contract Clone {
    /// @notice Reads an immutable arg with type address
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgAddress(uint256 argOffset)
        internal
        pure
        returns (address arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        assembly {
            arg := shr(0x60, calldataload(add(offset, argOffset)))
        }
    }
    /// @notice Reads an immutable arg with type uint256
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint256(uint256 argOffset)
        internal
        pure
        returns (uint256 arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := calldataload(add(offset, argOffset))
        }
    }
    /// @notice Reads an immutable arg with type uint64
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint64(uint256 argOffset)
        internal
        pure
        returns (uint64 arg)
    {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := shr(0xc0, calldataload(add(offset, argOffset)))
        }
    }
    /// @notice Reads an immutable arg with type uint8
    /// @param argOffset The offset of the arg in the packed data
    /// @return arg The arg value
    function _getArgUint8(uint256 argOffset) internal pure returns (uint8 arg) {
        uint256 offset = _getImmutableArgsOffset();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            arg := shr(0xf8, calldataload(add(offset, argOffset)))
        }
    }
    /// @return offset The offset of the packed immutable args in calldata
    function _getImmutableArgsOffset() internal pure returns (uint256 offset) {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            offset := sub(
                calldatasize(),
                add(shr(240, calldataload(sub(calldatasize(), 2))), 2)
            )
        }
    }
}
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;
import {Clone} from "Clone.sol";
/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 is Clone {
    /*///////////////////////////////////////////////////////////////
                                  EVENTS
    //////////////////////////////////////////////////////////////*/
    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 amount
    );
    /*///////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/
    uint256 public totalSupply;
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    /*///////////////////////////////////////////////////////////////
                               METADATA
    //////////////////////////////////////////////////////////////*/
    function name() external pure returns (string memory) {
        return string(abi.encodePacked(_getArgUint256(0)));
    }
    function symbol() external pure returns (string memory) {
        return string(abi.encodePacked(_getArgUint256(0x20)));
    }
    function decimals() external pure returns (uint8) {
        return _getArgUint8(0x40);
    }
    /*///////////////////////////////////////////////////////////////
                              ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/
    function approve(address spender, uint256 amount)
        public
        virtual
        returns (bool)
    {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }
    function transfer(address to, uint256 amount)
        public
        virtual
        returns (bool)
    {
        balanceOf[msg.sender] -= amount;
        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }
        emit Transfer(msg.sender, to, amount);
        return true;
    }
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.
        if (allowed != type(uint256).max)
            allowance[from][msg.sender] = allowed - amount;
        balanceOf[from] -= amount;
        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }
        emit Transfer(from, to, amount);
        return true;
    }
    /*///////////////////////////////////////////////////////////////
                       INTERNAL LOGIC
    //////////////////////////////////////////////////////////////*/
    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;
        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }
        emit Transfer(address(0), to, amount);
    }
    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;
        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }
        emit Transfer(from, address(0), amount);
    }
    function _getImmutableVariablesOffset()
        internal
        pure
        returns (uint256 offset)
    {
        assembly {
            offset := sub(
                calldatasize(),
                add(shr(240, calldataload(sub(calldatasize(), 2))), 2)
            )
        }
    }
}
// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;
import {ERC20} from "ERC20.sol";
/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Gnosis (https://github.com/gnosis/gp-v2-contracts/blob/main/src/contracts/libraries/GPv2SafeERC20.sol)
/// @dev Use with caution! Some functions in this library knowingly create dirty bits at the destination of the free memory pointer.
/// @dev Note that none of the functions in this library check that a token has code at all! That responsibility is delegated to the caller.
library SafeTransferLib {
    /*///////////////////////////////////////////////////////////////
                            ETH OPERATIONS
    //////////////////////////////////////////////////////////////*/
    function safeTransferETH(address to, uint256 amount) internal {
        bool callStatus;
        assembly {
            // Transfer the ETH and store if it succeeded or not.
            callStatus := call(gas(), to, amount, 0, 0, 0, 0)
        }
        require(callStatus, "ETH_TRANSFER_FAILED");
    }
    /*///////////////////////////////////////////////////////////////
                           ERC20 OPERATIONS
    //////////////////////////////////////////////////////////////*/
    function safeTransferFrom(
        ERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)
            // Write the abi-encoded calldata to memory piece by piece:
            mstore(
                freeMemoryPointer,
                0x23b872dd00000000000000000000000000000000000000000000000000000000
            ) // Begin with the function selector.
            mstore(
                add(freeMemoryPointer, 4),
                and(from, 0xffffffffffffffffffffffffffffffffffffffff)
            ) // Mask and append the "from" argument.
            mstore(
                add(freeMemoryPointer, 36),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            ) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 68), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
            // Call the token and store if it succeeded or not.
            // We use 100 because the calldata length is 4 + 32 * 3.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 100, 0, 0)
        }
        require(
            didLastOptionalReturnCallSucceed(callStatus),
            "TRANSFER_FROM_FAILED"
        );
    }
    function safeTransfer(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)
            // Write the abi-encoded calldata to memory piece by piece:
            mstore(
                freeMemoryPointer,
                0xa9059cbb00000000000000000000000000000000000000000000000000000000
            ) // Begin with the function selector.
            mstore(
                add(freeMemoryPointer, 4),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            ) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
            // Call the token and store if it succeeded or not.
            // We use 68 because the calldata length is 4 + 32 * 2.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
        }
        require(
            didLastOptionalReturnCallSucceed(callStatus),
            "TRANSFER_FAILED"
        );
    }
    function safeApprove(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;
        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)
            // Write the abi-encoded calldata to memory piece by piece:
            mstore(
                freeMemoryPointer,
                0x095ea7b300000000000000000000000000000000000000000000000000000000
            ) // Begin with the function selector.
            mstore(
                add(freeMemoryPointer, 4),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            ) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.
            // Call the token and store if it succeeded or not.
            // We use 68 because the calldata length is 4 + 32 * 2.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
        }
        require(didLastOptionalReturnCallSucceed(callStatus), "APPROVE_FAILED");
    }
    /*///////////////////////////////////////////////////////////////
                         INTERNAL HELPER LOGIC
    //////////////////////////////////////////////////////////////*/
    function didLastOptionalReturnCallSucceed(bool callStatus)
        private
        pure
        returns (bool success)
    {
        assembly {
            // Get how many bytes the call returned.
            let returnDataSize := returndatasize()
            // If the call reverted:
            if iszero(callStatus) {
                // Copy the revert message into memory.
                returndatacopy(0, 0, returnDataSize)
                // Revert with the same message.
                revert(0, returnDataSize)
            }
            switch returnDataSize
            case 32 {
                // Copy the return data into memory.
                returndatacopy(0, 0, returnDataSize)
                // Set success to whether it returned true.
                success := iszero(iszero(mload(0)))
            }
            case 0 {
                // There was no return data.
                success := 1
            }
            default {
                // It returned some malformed input.
                success := 0
            }
        }
    }
}
// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.4;
abstract contract Ownable {
    error Ownable_NotOwner();
    error Ownable_NewOwnerZeroAddress();
    address private _owner;
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );
    /// @dev Returns the address of the current owner.
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /// @dev Throws if called by any account other than the owner.
    modifier onlyOwner() {
        if (owner() != msg.sender) revert Ownable_NotOwner();
        _;
    }
    /// @dev Transfers ownership of the contract to a new account (`newOwner`).
    /// Can only be called by the current owner.
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) revert Ownable_NewOwnerZeroAddress();
        _transferOwnership(newOwner);
    }
    /// @dev Transfers ownership of the contract to a new account (`newOwner`).
    /// Internal function without access restriction.
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
/// @title Contains 512-bit math functions
/// @notice Facilitates multiplication and division that can have overflow of an intermediate value without any loss of precision
/// @dev Handles "phantom overflow" i.e., allows multiplication and division where an intermediate value overflows 256 bits
library FullMath {
    /// @notice Calculates floor(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
    /// @param a The multiplicand
    /// @param b The multiplier
    /// @param denominator The divisor
    /// @return result The 256-bit result
    /// @dev Credit to Remco Bloemen under MIT license https://xn--2-umb.com/21/muldiv
    function mulDiv(
        uint256 a,
        uint256 b,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = a * b
            // Compute the product mod 2**256 and mod 2**256 - 1
            // then use the Chinese Remainder Theorem to reconstruct
            // the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2**256 + prod0
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(a, b, not(0))
                prod0 := mul(a, b)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }
            // Handle non-overflow cases, 256 by 256 division
            if (prod1 == 0) {
                require(denominator > 0);
                assembly {
                    result := div(prod0, denominator)
                }
                return result;
            }
            // Make sure the result is less than 2**256.
            // Also prevents denominator == 0
            require(denominator > prod1);
            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////
            // Make division exact by subtracting the remainder from [prod1 prod0]
            // Compute remainder using mulmod
            uint256 remainder;
            assembly {
                remainder := mulmod(a, b, denominator)
            }
            // Subtract 256 bit number from 512 bit number
            assembly {
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }
            // Factor powers of two out of denominator
            // Compute largest power of two divisor of denominator.
            // Always >= 1.
            uint256 twos = (type(uint256).max - denominator + 1) & denominator;
            // Divide denominator by power of two
            assembly {
                denominator := div(denominator, twos)
            }
            // Divide [prod1 prod0] by the factors of two
            assembly {
                prod0 := div(prod0, twos)
            }
            // Shift in bits from prod1 into prod0. For this we need
            // to flip `twos` such that it is 2**256 / twos.
            // If twos is zero, then it becomes one
            assembly {
                twos := add(div(sub(0, twos), twos), 1)
            }
            prod0 |= prod1 * twos;
            // Invert denominator mod 2**256
            // Now that denominator is an odd number, it has an inverse
            // modulo 2**256 such that denominator * inv = 1 mod 2**256.
            // Compute the inverse by starting with a seed that is correct
            // correct for four bits. That is, denominator * inv = 1 mod 2**4
            uint256 inv = (3 * denominator) ^ 2;
            // Now use Newton-Raphson iteration to improve the precision.
            // Thanks to Hensel's lifting lemma, this also works in modular
            // arithmetic, doubling the correct bits in each step.
            inv *= 2 - denominator * inv; // inverse mod 2**8
            inv *= 2 - denominator * inv; // inverse mod 2**16
            inv *= 2 - denominator * inv; // inverse mod 2**32
            inv *= 2 - denominator * inv; // inverse mod 2**64
            inv *= 2 - denominator * inv; // inverse mod 2**128
            inv *= 2 - denominator * inv; // inverse mod 2**256
            // Because the division is now exact we can divide by multiplying
            // with the modular inverse of denominator. This will give us the
            // correct result modulo 2**256. Since the precoditions guarantee
            // that the outcome is less than 2**256, this is the final result.
            // We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inv;
            return result;
        }
    }
    /// @notice Calculates ceil(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
    /// @param a The multiplicand
    /// @param b The multiplier
    /// @param denominator The divisor
    /// @return result The 256-bit result
    function mulDivRoundingUp(
        uint256 a,
        uint256 b,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        result = mulDiv(a, b, denominator);
        unchecked {
            if (mulmod(a, b, denominator) > 0) {
                require(result < type(uint256).max);
                result++;
            }
        }
    }
}