设计一个自动售货机控制程序，它的投币口每次可以投入1元、2元、5元，且规定投入1元或2元后不得再投入5元。当投入总值等于或超过设定值（4元），售货机就自动送出货物并找回多余的钱。-design a vending machine control procedures, it can slot into each one yuan, the two yuan, 5 billion there are provisions into one yuan or two yuan may re-enter