Savings Account Class

An abstract base class Account is provided with pure virtual methods and a ready-made printBalance() method.

Create a class SavingsAccount that inherits from Account and:
- Has a constructor SavingsAccount(double initialBalance) that sets the starting balance
- Implements deposit(double amount): adds amount to the balance
- Implements withdraw(double amount): subtracts amount from the balance
- Implements getBalance(): returns the current balance

Do NOT write a main function.