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 program, which each time slot to be injected into the 1 yuan, 2 yuan, 5 yuan, and provides input 1 yuan or 2 yuan may not re-enter after 5. When gross investment is equal to or exceeds a set value (4 million), vending machine will automatically send the goods and recover the extra money.