// File: /D/repos/smart-contracts/Franklin/Fly-token/contracts/ERC1132.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.8.0;
/**
 * @title ERC1132 interface
 * @dev see https://github.com/ethereum/EIPs/issues/1132
 */

abstract contract ERC1132 {
    /**
     * @dev Reasons why a user's tokens have been locked
     */
    mapping(address => bytes32[]) public lockReason;

    /**
     * @dev locked token structure
     */
    struct lockToken {
        uint256 amount;
        uint256 validity;
        bool claimed;
    }

    /**
     * @dev Holds number & validity of tokens locked for a given reason for
     *      a specified address
     */
    mapping(address => mapping(bytes32 => lockToken)) public locked;

    /**
     * @dev Records data of all the tokens Locked
     */
    event Locked(
        address indexed _of,
        bytes32 indexed _reason,
        uint256 _amount,
        uint256 _validity
    );

    /**
     * @dev Records data of all the tokens unlocked
     */
    event Unlocked(
        address indexed _of,
        bytes32 indexed _reason,
        uint256 _amount
    );
    
    /**
     * @dev Locks a specified amount of tokens against an address,
     *      for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be locked
     * @param _time Lock time in seconds
     */
    function lock(bytes32 _reason, uint256 _amount, uint256 _time) virtual
        public returns (bool);
  
    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     */
    function tokensLocked(address _of, bytes32 _reason) virtual
        public view returns (uint256 amount);
    
    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason at a specific time
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     * @param _time The timestamp to query the lock tokens for
     */
    function tokensLockedAtTime(address _of, bytes32 _reason, uint256 _time) virtual
        public view returns (uint256 amount);
    
    /**
     * @dev Returns total tokens held by an address (locked + transferable)
     * @param _of The address to query the total balance of
     */
    function totalBalanceOf(address _of) virtual
        public view returns (uint256 amount);
    
    /**
     * @dev Extends lock for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _time Lock extension time in seconds
     */
    function extendLock(bytes32 _reason, uint256 _time) virtual
        public returns (bool);
    
    /**
     * @dev Increase number of tokens locked for a specified reason
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be increased
     */
    function increaseLockAmount(bytes32 _reason, uint256 _amount) virtual
        public returns (bool);

    /**
     * @dev Returns unlockable tokens for a specified address for a specified reason
     * @param _of The address to query the the unlockable token count of
     * @param _reason The reason to query the unlockable tokens for
     */
    function tokensUnlockable(address _of, bytes32 _reason) virtual
        public view returns (uint256 amount);
 
    /**
     * @dev Unlocks the unlockable tokens of a specified address
     * @param _of Address of user, claiming back unlockable tokens
     */
    function unlock(address _of) virtual
        public returns (uint256 unlockableTokens);

    /**
     * @dev Gets the unlockable tokens of a specified address
     * @param _of The address to query the the unlockable token count of
     */
    function getUnlockableTokens(address _of) virtual
        public view returns (uint256 unlockableTokens);

}
// File: /D/repos/smart-contracts/Franklin/Fly-token/contracts/FLyToken.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.8.0;
import "../contracts/LockableToken.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract FLyToken is LockableToken, Ownable {

    /**
     * @dev Indicates that the contract has been initialized with locked tokens for round 1.
     */
    bool private _initializedRound1;

    /**
     * @dev Indicates that the contract is in the process of being initialized for round 1.
     */
    bool private _initializingRound1;

    /**
     * @dev Indicates that the contract has been initialized with locked tokens for round 2.
     */
    bool private _initializedRound2;

    /**
     * @dev Indicates that the contract is in the process of being initialized for round 2.
     */
    bool private _initializingRound2;

    constructor() public LockableToken(17011706000000, "Franklin", "FLy", 4) {
    }

    function initializeRound1() public initializerR1 onlyOwner  {
        _initRound1();
    }

    function initializeRound2() public initializerR2 onlyOwner  {
        _initRound2();
    }

    function _initRound1() internal   {
        uint256 vestingRound1Seconds = 1617235200 - now;
        uint256 vrAmount = 63964014560;
        uint256 days30 = 2592000;
        //round 1
        _lock('v1_1', vrAmount, vestingRound1Seconds);
        _lock('v1_2', vrAmount, vestingRound1Seconds.add(days30));
        _lock('v1_3', vrAmount, vestingRound1Seconds.add(days30.mul(2)));
        _lock('v1_4', vrAmount, vestingRound1Seconds.add(days30.mul(3)));
        _lock('v1_5', vrAmount, vestingRound1Seconds.add(days30.mul(4)));
        _lock('v1_6', vrAmount, vestingRound1Seconds.add(days30.mul(5)));
        _lock('v1_7', vrAmount, vestingRound1Seconds.add(days30.mul(6)));
        _lock('v1_8', vrAmount, vestingRound1Seconds.add(days30.mul(7)));
        _lock('v1_9', vrAmount, vestingRound1Seconds.add(days30.mul(8)));
        _lock('v1_10', vrAmount, vestingRound1Seconds.add(days30.mul(9)));
        _lock('v1_11', vrAmount, vestingRound1Seconds.add(days30.mul(10)));
        _lock('v1_12', vrAmount, vestingRound1Seconds.add(days30.mul(11)));
        _lock('v1_13', vrAmount, vestingRound1Seconds.add(days30.mul(12)));
        _lock('v1_14', vrAmount, vestingRound1Seconds.add(days30.mul(13)));
        _lock('v1_15', vrAmount, vestingRound1Seconds.add(days30.mul(14)));
        _lock('v1_16', vrAmount, vestingRound1Seconds.add(days30.mul(15)));
        _lock('v1_17', vrAmount, vestingRound1Seconds.add(days30.mul(16)));
        _lock('v1_18', vrAmount, vestingRound1Seconds.add(days30.mul(17)));
        _lock('v1_19', vrAmount, vestingRound1Seconds.add(days30.mul(18)));
        _lock('v1_20', vrAmount, vestingRound1Seconds.add(days30.mul(19)));
        _lock('v1_21', vrAmount, vestingRound1Seconds.add(days30.mul(20)));
        _lock('v1_22', vrAmount, vestingRound1Seconds.add(days30.mul(21)));
        _lock('v1_23', vrAmount, vestingRound1Seconds.add(days30.mul(22)));
        _lock('v1_24', vrAmount, vestingRound1Seconds.add(days30.mul(23)));
        _lock('v1_25', vrAmount, vestingRound1Seconds.add(days30.mul(24)));
        _lock('v1_26', vrAmount, vestingRound1Seconds.add(days30.mul(25)));
        _lock('v1_27', vrAmount, vestingRound1Seconds.add(days30.mul(26)));
        _lock('v1_28', vrAmount, vestingRound1Seconds.add(days30.mul(27)));
        _lock('v1_29', vrAmount, vestingRound1Seconds.add(days30.mul(28)));
        _lock('v1_30', vrAmount, vestingRound1Seconds.add(days30.mul(29)));
        _lock('v1_31', vrAmount, vestingRound1Seconds.add(days30.mul(30)));
        _lock('v1_32', vrAmount, vestingRound1Seconds.add(days30.mul(31)));
        _lock('v1_33', vrAmount, vestingRound1Seconds.add(days30.mul(32)));
        _lock('v1_34', vrAmount, vestingRound1Seconds.add(days30.mul(33)));
        _lock('v1_35', vrAmount, vestingRound1Seconds.add(days30.mul(34)));
        _lock('v1_36', vrAmount, vestingRound1Seconds.add(days30.mul(35)));
        _lock('v1_37', vrAmount, vestingRound1Seconds.add(days30.mul(36)));
        _lock('v1_38', vrAmount, vestingRound1Seconds.add(days30.mul(37)));
        _lock('v1_39', vrAmount, vestingRound1Seconds.add(days30.mul(38)));
        _lock('v1_40', vrAmount, vestingRound1Seconds.add(days30.mul(39)));
        _lock('v1_41', vrAmount, vestingRound1Seconds.add(days30.mul(40)));
        _lock('v1_42', vrAmount, vestingRound1Seconds.add(days30.mul(41)));
        _lock('v1_43', vrAmount, vestingRound1Seconds.add(days30.mul(42)));
        _lock('v1_44', vrAmount, vestingRound1Seconds.add(days30.mul(43)));
        _lock('v1_45', vrAmount, vestingRound1Seconds.add(days30.mul(44)));
        _lock('v1_46', vrAmount, vestingRound1Seconds.add(days30.mul(45)));
        _lock('v1_47', vrAmount, vestingRound1Seconds.add(days30.mul(46)));
        _lock('v1_48', vrAmount, vestingRound1Seconds.add(days30.mul(47)));
        _lock('v1_49', vrAmount, vestingRound1Seconds.add(days30.mul(48)));
        _lock('v1_50', vrAmount, vestingRound1Seconds.add(days30.mul(49)));
        //round 1: transfer locked total 
        transfer(address(this), 3198200728000);
    }

    function _initRound2() internal   {
        uint256 vestingRound2Seconds = 1625097600 - now;
        uint256 days30 = 2592000;
        // round 2 - starting from 01.07.2021 - autogenerated from excel output
        _lock('v2_1', 29770485500, vestingRound2Seconds);
        _lock('v2_2', 30365895210, vestingRound2Seconds.add(days30));
        _lock('v2_3', 30978316626, vestingRound2Seconds.add(days30.mul(2)));
        _lock('v2_4', 31590738042, vestingRound2Seconds.add(days30.mul(3)));
        _lock('v2_5', 32220171164, vestingRound2Seconds.add(days30.mul(4)));
        _lock('v2_6', 32866615992, vestingRound2Seconds.add(days30.mul(5)));
        _lock('v2_7', 33530072526, vestingRound2Seconds.add(days30.mul(6)));
        _lock('v2_8', 34193529060, vestingRound2Seconds.add(days30.mul(7)));
        _lock('v2_9', 34873997300, vestingRound2Seconds.add(days30.mul(8)));
        _lock('v2_10', 35571477246, vestingRound2Seconds.add(days30.mul(9)));
        _lock('v2_11', 36285968898, vestingRound2Seconds.add(days30.mul(10)));
        _lock('v2_12', 37017472256, vestingRound2Seconds.add(days30.mul(11)));
        _lock('v2_13', 37748975614, vestingRound2Seconds.add(days30.mul(12)));
        _lock('v2_14', 38514502384, vestingRound2Seconds.add(days30.mul(13)));
        _lock('v2_15', 39280029154, vestingRound2Seconds.add(days30.mul(14)));
        _lock('v2_16', 40062567630, vestingRound2Seconds.add(days30.mul(15)));
        _lock('v2_17', 40862117812, vestingRound2Seconds.add(days30.mul(16)));
        _lock('v2_18', 41678679700, vestingRound2Seconds.add(days30.mul(17)));
        _lock('v2_19', 42512253294, vestingRound2Seconds.add(days30.mul(18)));
        _lock('v2_20', 43362838594, vestingRound2Seconds.add(days30.mul(19)));
        _lock('v2_21', 44230435600, vestingRound2Seconds.add(days30.mul(20)));
        _lock('v2_22', 45115044312, vestingRound2Seconds.add(days30.mul(21)));
        _lock('v2_23', 46016664730, vestingRound2Seconds.add(days30.mul(22)));
        _lock('v2_24', 46952308560, vestingRound2Seconds.add(days30.mul(23)));
        _lock('v2_25', 47887952390, vestingRound2Seconds.add(days30.mul(24)));
        _lock('v2_26', 48840607926, vestingRound2Seconds.add(days30.mul(25)));
        _lock('v2_27', 49810275168, vestingRound2Seconds.add(days30.mul(26)));
        _lock('v2_28', 50813965822, vestingRound2Seconds.add(days30.mul(27)));
        _lock('v2_29', 51834668182, vestingRound2Seconds.add(days30.mul(28)));
        _lock('v2_30', 52872382248, vestingRound2Seconds.add(days30.mul(29)));
        _lock('v2_31', 53927108020, vestingRound2Seconds.add(days30.mul(30)));
        _lock('v2_32', 54998845498, vestingRound2Seconds.add(days30.mul(31)));
        _lock('v2_33', 56104606388, vestingRound2Seconds.add(days30.mul(32)));
        _lock('v2_34', 57227378984, vestingRound2Seconds.add(days30.mul(33)));
        _lock('v2_35', 58367163286, vestingRound2Seconds.add(days30.mul(34)));
        _lock('v2_36', 59540971000, vestingRound2Seconds.add(days30.mul(35)));
        _lock('v2_37', 60731790420, vestingRound2Seconds.add(days30.mul(36)));
        _lock('v2_38', 61939621546, vestingRound2Seconds.add(days30.mul(37)));
        _lock('v2_39', 63181476084, vestingRound2Seconds.add(days30.mul(38)));
        _lock('v2_40', 64440342328, vestingRound2Seconds.add(days30.mul(39)));
        _lock('v2_41', 65733231984, vestingRound2Seconds.add(days30.mul(40)));
        _lock('v2_42', 67043133346, vestingRound2Seconds.add(days30.mul(41)));
        _lock('v2_43', 68387058120, vestingRound2Seconds.add(days30.mul(42)));
        _lock('v2_44', 69765006306, vestingRound2Seconds.add(days30.mul(43)));
        _lock('v2_45', 71159966198, vestingRound2Seconds.add(days30.mul(44)));
        _lock('v2_46', 72571937796, vestingRound2Seconds.add(days30.mul(45)));
        _lock('v2_47', 74034944512, vestingRound2Seconds.add(days30.mul(46)));
        _lock('v2_48', 94823249244, vestingRound2Seconds.add(days30.mul(47)));
        //round 2: transfer locked total 
        transfer(address(this), 2381638840000);
    }

    function _lock(
        bytes32 _reason,
        uint256 _amount,
        uint256 _time
    ) internal returns (bool) {
        uint256 validUntil = now.add(_time); //solhint-disable-line
        if (locked[_msgSender()][_reason].amount == 0)
            lockReason[_msgSender()].push(_reason);
        locked[_msgSender()][_reason] = lockToken(_amount, validUntil, false);
        return true;
    }


    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override {
        super._beforeTokenTransfer(from, to, amount);
        unlock(from);
    }

    /**
    * @dev Modifier to protect an initializer function from being invoked twice.
    */
    modifier initializerR1() {
        require(_initializingRound1 || !_initializedRound1, "InitializerR1: contract is already initialized");

        bool isTopLevelCall = !_initializingRound1;
        if (isTopLevelCall) {
            _initializingRound1 = true;
            _initializedRound1 = true;
        }

        _;

        if (isTopLevelCall) {
            _initializingRound1 = false;
        }
    }

    /**
    * @dev Modifier to protect an initializer function from being invoked twice.
    */
    modifier initializerR2() {
        require(_initializingRound2 || !_initializedRound2, "InitializerR2: contract is already initialized");

        bool isTopLevelCall = !_initializingRound2;
        if (isTopLevelCall) {
            _initializingRound2 = true;
            _initializedRound2 = true;
        }

        _;

        if (isTopLevelCall) {
            _initializingRound2 = false;
        }
    }
}

// File: /D/repos/smart-contracts/Franklin/Fly-token/contracts/LockableToken.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.8.0;
import "../contracts/ERC1132.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20Burnable.sol";

contract LockableToken is ERC1132, ERC20Burnable {
    /**
     * @dev Error messages for require statements
     */
    string internal constant ALREADY_LOCKED = "Tokens already locked";
    string internal constant NOT_LOCKED = "No tokens locked";
    string internal constant AMOUNT_ZERO = "Amount can not be 0";

    /**
     * @dev constructor to mint initial tokens
     * Shall update to _mint once openzepplin updates their npm package.
     */
    constructor(
        uint256 _supply,
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) public ERC20(_name, _symbol) {
        _setupDecimals(_decimals);
        _mint(_msgSender(), _supply);
    }

    /**
     * @dev Locks a specified amount of tokens against an address,
     *      for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be locked
     * @param _time Lock time in seconds
     */
    function lock(
        bytes32 _reason,
        uint256 _amount,
        uint256 _time
    ) public override returns (bool) {
        uint256 validUntil = now.add(_time); //solhint-disable-line

        // If tokens are already locked, then functions extendLock or
        // increaseLockAmount should be used to make any changes
        require(tokensLocked(_msgSender(), _reason) == 0, ALREADY_LOCKED);
        require(_amount != 0, AMOUNT_ZERO);

        if (locked[_msgSender()][_reason].amount == 0)
            lockReason[_msgSender()].push(_reason);

        transfer(address(this), _amount);

        locked[_msgSender()][_reason] = lockToken(_amount, validUntil, false);

        emit Locked(_msgSender(), _reason, _amount, validUntil);
        return true;
    }

    /**
     * @dev Transfers and Locks a specified amount of tokens,
     *      for a specified reason and time
     * @param _to adress to which tokens are to be transfered
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be transfered and locked
     * @param _time Lock time in seconds
     */
    function transferWithLock(
        address _to,
        bytes32 _reason,
        uint256 _amount,
        uint256 _time
    ) public returns (bool) {
        uint256 validUntil = now.add(_time); //solhint-disable-line

        require(tokensLocked(_to, _reason) == 0, ALREADY_LOCKED);
        require(_amount != 0, AMOUNT_ZERO);

        if (locked[_to][_reason].amount == 0) lockReason[_to].push(_reason);

        transfer(address(this), _amount);

        locked[_to][_reason] = lockToken(_amount, validUntil, false);

        emit Locked(_to, _reason, _amount, validUntil);
        return true;
    }

    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     */
    function tokensLocked(address _of, bytes32 _reason)
        public
        view
        override
        returns (uint256 amount)
    {
        if (!locked[_of][_reason].claimed) amount = locked[_of][_reason].amount;
    }

    /**
     * @dev Returns tokens locked for a specified address for a
     *      specified reason at a specific time
     *
     * @param _of The address whose tokens are locked
     * @param _reason The reason to query the lock tokens for
     * @param _time The timestamp to query the lock tokens for
     */
    function tokensLockedAtTime(
        address _of,
        bytes32 _reason,
        uint256 _time
    ) public view override returns (uint256 amount) {
        if (locked[_of][_reason].validity > _time)
            amount = locked[_of][_reason].amount;
    }

    /**
     * @dev Returns total tokens held by an address (locked + transferable)
     * @param _of The address to query the total balance of
     */
    function totalBalanceOf(address _of)
        public
        view
        override
        returns (uint256 amount)
    {
        amount = balanceOf(_of);

        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            amount = amount.add(tokensLocked(_of, lockReason[_of][i]));
        }
    }

    /**
     * @dev Extends lock for a specified reason and time
     * @param _reason The reason to lock tokens
     * @param _time Lock extension time in seconds
     */
    function extendLock(bytes32 _reason, uint256 _time)
        public
        override
        returns (bool)
    {
        require(tokensLocked(_msgSender(), _reason) > 0, NOT_LOCKED);

        locked[_msgSender()][_reason].validity = locked[_msgSender()][_reason]
            .validity
            .add(_time);

        emit Locked(
            _msgSender(),
            _reason,
            locked[_msgSender()][_reason].amount,
            locked[_msgSender()][_reason].validity
        );
        return true;
    }

    /**
     * @dev Increase number of tokens locked for a specified reason
     * @param _reason The reason to lock tokens
     * @param _amount Number of tokens to be increased
     */
    function increaseLockAmount(bytes32 _reason, uint256 _amount)
        public
        override
        returns (bool)
    {
        require(tokensLocked(_msgSender(), _reason) > 0, NOT_LOCKED);
        transfer(address(this), _amount);

        locked[_msgSender()][_reason].amount = locked[_msgSender()][_reason]
            .amount
            .add(_amount);

        emit Locked(
            _msgSender(),
            _reason,
            locked[_msgSender()][_reason].amount,
            locked[_msgSender()][_reason].validity
        );
        return true;
    }

    /**
     * @dev Returns unlockable tokens for a specified address for a specified reason
     * @param _of The address to query the the unlockable token count of
     * @param _reason The reason to query the unlockable tokens for
     */
    function tokensUnlockable(address _of, bytes32 _reason)
        public
        view
        override
        returns (uint256 amount)
    {
        if (
            locked[_of][_reason].validity <= now &&
            !locked[_of][_reason].claimed
        )
            //solhint-disable-line
            amount = locked[_of][_reason].amount;
    }

    /**
     * @dev Unlocks the unlockable tokens of a specified address
     * @param _of Address of user, claiming back unlockable tokens
     */
    function unlock(address _of)
        public
        override
        returns (uint256 unlockableTokens)
    {
        uint256 lockedTokens;

        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            lockedTokens = tokensUnlockable(_of, lockReason[_of][i]);
            if (lockedTokens > 0) {
                unlockableTokens = unlockableTokens.add(lockedTokens);
                locked[_of][lockReason[_of][i]].claimed = true;
                emit Unlocked(_of, lockReason[_of][i], lockedTokens);
            }
        }

        if (unlockableTokens > 0) this.transfer(_of, unlockableTokens);
    }

    /**
     * @dev Gets the unlockable tokens of a specified address
     * @param _of The address to query the the unlockable token count of
     */
    function getUnlockableTokens(address _of)
        public
        view
        override
        returns (uint256 unlockableTokens)
    {
        for (uint256 i = 0; i < lockReason[_of].length; i++) {
            unlockableTokens = unlockableTokens.add(
                tokensUnlockable(_of, lockReason[_of][i])
            );
        }
    }
}

// File: @openzeppelin/contracts/GSN/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/*
 * @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 GSN 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 payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

import "../GSN/Context.sol";
/**
 * @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.
 */
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 () internal {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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 sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @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) {
        // 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 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

import "../../GSN/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";

/**
 * @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 {
    using SafeMath for uint256;
    using Address for address;

    mapping (address => uint256) private _balances;

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
    }

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

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view 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 {_setupDecimals} is
     * called.
     *
     * 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 returns (uint8) {
        return _decimals;
    }

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

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view 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);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        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].add(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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is 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);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(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
     *
     * - `to` 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 = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(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);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(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 Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @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 to 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 { }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20Burnable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

import "../../GSN/Context.sol";
import "./ERC20.sol";

/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract ERC20Burnable is Context, ERC20 {
    /**
     * @dev Destroys `amount` tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 amount) public virtual {
        _burn(_msgSender(), amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
     * allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for ``accounts``'s tokens of at least
     * `amount`.
     */
    function burnFrom(address account, uint256 amount) public virtual {
        uint256 decreasedAllowance = allowance(account, _msgSender()).sub(amount, "ERC20: burn amount exceeds allowance");

        _approve(account, _msgSender(), decreasedAllowance);
        _burn(account, amount);
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @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/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}