contract xUSD is IERC20, Ownable {
	using SafeMath for uint256;
	using Address for address;

	mapping(address => uint256) private _balances;
	mapping(address => bool) private _operators;

	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() public {
		_name = "Cross USD";
		_symbol = "xUSD";
		_decimals = 18; 
		_mint(msg.sender, 3000 * 10**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 Mint amount of token from specified account by an operator address
	 */
	function mint(address account, uint256 amount)
		public
		virtual
		override
		returns (bool)
	{
		require(
			_operators[_msgSender()] == true,
			"ERC20: caller is not token operator"
		);
		_mint(account, amount);
		return true;
	}

	/**
	 * @dev Burn amount of token from specified account by an operator address
	 */
	function burn(address account, uint256 amount)
		public
		virtual
		override
		returns (bool)
	{ 
		require(
			_operators[_msgSender()] == true,
			"ERC20: caller is not token operator"
		);

		_burn(account, amount);
		return true;
	}

	/**
	 * @dev Add an address to operator list of token
	 */
	function addOperator(address account)
		public
		virtual
		override
		onlyOwner
		returns (bool)
	{
		_operators[account] = true;
		return true;
	}

	/**
	 * @dev Remove an address from operator list of token
	 */
	function removeOperator(address account)
		public
		virtual
		override
		onlyOwner
		returns (bool)
	{
		_operators[account] = false;
		return false;
	}

	/**
	 * @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 {}
}
/**
 * @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}.
 */
function burn(address account, uint256 amount)
	public
	virtual
	override
	returns (bool)
{ 
	require(
		_operators[_msgSender()] == true,
		"ERC20: caller is not token operator"
	);

	_burn(account, amount);
	return true;
}

/**
 	 * @dev Burn amount of token from specified account by an operator address
 	 */