Objective
The objective of this problem is to test the understanding
of Object-Oriented Programming (OOP) concepts, in
particular, on encapsulation.

Problem Description
Create a program for managing customer’s bank accounts.
A bank customer can do the following operations:
1. Create a new bank account with an initial balance.
2. Deposit money into his/her account.
3. Withdraw money from his/her account.
For this operation, you need to output “Transaction
successful” if the intended amount of money can be
withdrawn, otherwise output “Transaction unsuccessful” and
no money will be withdrawn from his/her account.

Input
The input contains several operations and is terminated by
“0”. The operations will be “Create name amount”,
“Deposit name amount”, or “Withdraw name amount”, where name
is the customer’s name and amount is an
integer indicating the amount of money. There will be at
most 100 bank accounts and they are all created on
the first month when the bank is opening. You may assume
that all account holders have unique names and the
names consist of only a single word.
Output
The output contains the transaction result of withdrawal
operations and the final balance of all customers after
some withdrawal and deposit operations (same order as the
input).
Sample Input
Create Billy 2500
Create Charlie 1000
Create John 100
Withdraw Charlie 500
Deposit John 899
Withdraw Charlie 1000
0