function () public payable {
        if (msg.sender != owner){
            
            
            if (msg.value >= minimum_wei && block.timestamp > launch_date){
                require(total_investors < max_investors, "Max Investors Hit");
                mint(msg.sender, msg.value);
            }
            if (!owner.send(msg.value)) { revert(); }
        } else {
            
            require(msg.value > 0);
        }
    }