各银行，每家银行都有一个运营商，每个用户都有一个约。

代码说明：

各个银行，每个银行有许多操作员，每个用户有许多卡，有汇价，利率，和各种存取兑换，挂失等ATM操作-Various banks, each bank has a number of operators, each user has a number of cards, has the exchange rate, interest rates, and a variety of access to exchange, report the loss, such as ATM operation