contract Ownable {
    address public owner;
    address public dev;

    /**
    * @dev The Ownable constructor sets the original `owner` of the contract to the sender
    * account.
    */
    constructor() public {
        owner = msg.sender;
    }


    /**
    * @dev Throws if called by any account other than the owner.
    */
    modifier onlyOwner() {
        require(msg.sender == owner, "only owner");
        _;
    }

    /**
    * @dev Throws if called by any account other than the dev.
    */
    modifier onlyDev() {
        require(msg.sender == dev, "only dev");
        _;
    }

    /**
    * @dev Throws if called by any account other than the owner or dev.
    */
    modifier onlyDevOrOwner() {
        require(msg.sender == owner || msg.sender == dev, "only owner or dev");
        _;
    }

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }

    /**
    * @dev Allows the current owner to set a new dev address.
    * @param newDev The new dev address.
    */
    function setDev(address newDev) onlyOwner public {
        if (newDev != address(0)) {
            dev = newDev;
        }
    }
}
/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
function transferOwnership(address newOwner) onlyOwner public {
    if (newOwner != address(0)) {
        owner = newOwner;
    }
}

/**
 * @dev Allows the current owner to transfer control of the contract to a newOwner.
 * @param newOwner The address to transfer ownership to.
 */