def caidan():
    total = []
    while True:
        unit= input("请输入：")
        if unit== 'q':
            break
        else:
            try:
                unit1 = int(unit)
            except:
                print("输入错误请重新输入")
            else:
                total.append(unit1)
    return total
# a = caidan()
# print(sum(a))