using System;

public class Program{

public class BankAccount

{

private decimal _balance;

private string _pin;

public BankAccount(decimal initialBalance, string pin)

{

_balance = initialBalance;

_pin = pin;

}

public void Deposit(decimal amount)

{

_balance += amount;

}

public bool Withdraw(decimal amount)

{

if (amount > _balance)

{

return false;

}

_balance -= amount;

return true;

}

public decimal GetBalance()

{

return _balance;

}

public bool ChangePin(string oldPin, string newPin)

{

if (_pin != oldPin)

{

return false;

}

_pin = newPin;

return true;

}
  }
// Main method for testing

public static void Main(string[] args)

{

BankAccount account = new BankAccount(1000m, "1234");

Console.WriteLine("Initial Balance: " + account.GetBalance());

// Deposit test

account.Deposit(500m);

Console.WriteLine("After Deposit: " + account.GetBalance());

// Withdraw test

bool withdrawSuccess = account.Withdraw(300m);

Console.WriteLine("Withdraw 300 Successful: " + withdrawSuccess);

Console.WriteLine("Balance After Withdrawal: " + account.GetBalance());

// Withdraw exceeding balance

bool failedWithdraw = account.Withdraw(2000m);

Console.WriteLine("Withdraw 2000 Successful: " + failedWithdraw);

Console.WriteLine("Balance After Failed Withdrawal: " + account.GetBalance());

// Change PIN test

bool pinChanged = account.ChangePin("1234", "5678");

Console.WriteLine("PIN Changed: " + pinChanged);

// Wrong old PIN test

bool failedPinChange = account.ChangePin("1111", "9999");

Console.WriteLine("PIN Changed with Wrong Old PIN: " + failedPinChange);

}
}