while 1:
    money = input("insert coin=>")
    number = input("select beverage\n")
    money = int(money)
    temp = money
    if number == "1":
        #grape 100
        print("you choose grape. change is ",money-100,"coin")
        money = temp-100 #callculate change
        if money <= 0:  #check money
            break
    elif number == "2":
        #orange 200
        print("you choose orange. change is ",money-200,"coin")
        money = temp-200 #callculate change
        if money <= 0:  #check money
            break
    elif number == "3":
        #fanta 300
        print("you choose fanta. change is ",money-300,"coin")
        money = temp-300 #callculate change
        if money <= 0: #check money
            break
    else:
        #wrong sellection
        print("wrong number. please select again")