pragma solidity >=0.4.21 <0.7.0;

/**
 * @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.
     *
     * _Available since v2.4.0._
     */
    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.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        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.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}
contract Ownable {

    address private _owner;

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

    constructor() internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    modifier onlyOwner() {
        require(msg.sender == _owner, "Ownable: caller is not the owner");
        _;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }

}

library Address {

    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly { size := extcodesize(account) } //solium-disable-line security/no-inline-assembly
        return size > 0;
    }

    function toPayable(address account) internal pure returns (address payable) {
        return address(uint160(account));
    }

}
interface IERC20 {

    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

}
contract ETOCoin is Ownable, IERC20 {

    using SafeMath for uint256;
    using Address for address;

    string public constant name = 'Electustok';
    string public constant symbol = 'ETO';
    uint256 public constant decimals = 18;
    uint256 public constant totalSupply = 6400 * 10000 * 10 ** decimals;

    uint256 public constant FounderAllocation = 6400 * 10000 * 10 ** decimals;
    uint256 public constant FounderActivitytyAmount = 220 * 10000 * 10 ** decimals;
    uint256 public constant FounderLockupAmount = 180 * 10000 * 10 ** decimals;
    uint256 public constant FounderLockupCliff = 180 days;
    uint256 public constant FounderReleaseAmount = 30 * 10000 * 10 ** decimals;
    uint256 public constant FounderReleaseInterval = 30 days;

    address public founder = address(0);
    uint256 public founderLockupStartTime = 0;
    uint256 public founderReleasedAmount = 0;

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

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed from, address indexed to, uint256 value);
    event ChangeFounder(address indexed previousFounder, address indexed newFounder);
    event SetMinter(address indexed minter);
    //only this accout[0] can't transfer
    constructor(address _founder, address _operator) public {
        require(_founder != address(0), "founder is the zero address");
        require(_operator != address(0), "operator is the zero address");
        founder = _founder;
        founderLockupStartTime = block.timestamp;
        _balances[address(this)] = totalSupply;
        _transfer(address(this), _operator, FounderAllocation.sub(FounderLockupAmount));
    }

    function release() public {
        //get the current timestamp
        uint256 currentTime = block.timestamp;
        uint256 cliffTime = founderLockupStartTime.add(FounderLockupCliff);
        //when the time not reached then return
        if (currentTime < cliffTime) return;
        //over the base return
        if (founderReleasedAmount >= FounderLockupAmount) return;
        uint256 month = currentTime.sub(cliffTime).div(FounderReleaseInterval);
        uint256 releaseAmount = month.mul(FounderReleaseAmount);
        //freed every month
        if (releaseAmount > FounderLockupAmount) releaseAmount = FounderLockupAmount;
        if (releaseAmount <= founderReleasedAmount) return;
        uint256 amount = releaseAmount.sub(founderReleasedAmount);
        founderReleasedAmount = releaseAmount;
        _transfer(address(this), founder, amount);
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function transfer(address to, uint256 amount) public returns (bool) {
        _transfer(msg.sender, to, amount);
        return true;
    }

    function allowance(address from, address to) public view returns (uint256) {
        return _allowances[from][to];
    }

    function approve(address to, uint256 amount) public returns (bool) {
        _approve(msg.sender, to, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) public returns (bool) {
        uint256 remaining = _allowances[from][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance");

        _transfer(from, to, amount);
        _approve(from, msg.sender, remaining);
        return true;
    }

    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _balances[from] = _balances[from].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[to] = _balances[to].add(amount);
        emit Transfer(from, to, amount);
    }

    function _approve(address from, address to, uint256 amount) private {
        require(from != address(0), "ERC20: approve from the zero address");
        require(to != address(0), "ERC20: approve to the zero address");

        _allowances[from][to] = amount;
        emit Approval(from, to, amount);
    }

    function changeFounder(address _founder) public onlyOwner {
        require(_founder != address(0), "ElectustokCoin: founder is the zero address");

        emit ChangeFounder(founder, _founder);
        founder = _founder;
    }

    function setMinter(address minter) public onlyOwner {
        require(minter != address(0), "ElectustokCoin: minter is the zero address");
        require(minter.isContract(), "ElectustokCoin: minter is not contract");
        _transfer(address(this), minter, totalSupply.sub(FounderAllocation));
        emit SetMinter(minter);
    }

}

{
  "compilationTarget": {
    "ETOCoin.sol": "ETOCoin"
  },
  "evmVersion": "petersburg",
  "libraries": {},
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}