Here are requirments: When transferring money, a VIP account can transfer at most 20000 and a normal account can transfer at most 10000. It is assumed that the accounts transferring from and transferring to are all in the account.txt. If the “from”account is VIP, the charge for the transaction is 0.5%; otherwise, the charge is 1%.
and the account.txt could be like this
0001 Amy 40000 V
0002 Nels 80000 V

0023 Tim 3400 N
0024 Cherry 3500 N