客户业务分2种，第一种是申请从银行得到一笔资金，即借款或取款。第2种是向银行投入一笔资金，即存款或还款。银行有2个服务窗口，相应地有2个队列。客户到达银行后先排第一个队。处理每个客户业务时，如果属于第一种，且申请额超出银行现存资金总额而得不到满足，则立刻排入第2个队等候，直至满足时才离开银行，否则业务处理完后立刻离开银行。每接待完一个第二种业务的客户，则顺序检查和处理（如果可能）第二个队列中的客户，对能满足的申请者予以满足，不能满足者重新排到第二个队列的队尾。注意，在此检查过程中，一旦银行资金总额少于或等于刚才第一个队列中最后一个客户（第2种业务）被接待之前的数额，或者本次以将第2个队列检查或者处理了一遍，就停止检查（因为此时已不可能还有能满足者）转而继续接待第一个队列的客户。任何时刻都只能开一个窗口。假设检查不需要时间。营业时间结束时所有客户立即离开银行。

写一个上述银行业务的事件驱动模拟系统，通过模拟方法求出客户在银行内逗留的平均时间。

-Customer business points 2 kinds, the first kind is to apply for to get a money from the bank, namely borrowing or withdraw the funds. The second was put into a fund to the bank, namely deposit or reimbursement. The bank has 2 service window, correspondingly has 2 queue. Customer first row after reach the bank first team. Deal with each customer business, if belong to the first, and apply for the forehead is beyond Banks and can t get the total amount of funds existing met, then immediately into the second team waiting until meet do not leave the bank, or business processing after the bank to leave at once. Each reception after a second business customers, the order inspection and handling (if possible) the second queue of customer, can meet the applicants to be met, who can t meet again in the second row of queue of the queue. Note, ?