function burn(uint256 _value) public onlyOwner {
		require(!burnt);
		require(_value > 0);
		require(_value <= balances[msg.sender]);
		require(block.timestamp < 1690848000); 

		balances[msg.sender] = balances[msg.sender].sub(_value);
		totalSupply_ = totalSupply_.sub(_value);
		burnt = true;
		emit Burn(msg.sender, _value);
		emit Transfer(msg.sender, address(0), _value);
	}