using System;

    class BankAccount {

        private double balance=0;

        public void Deposit(double n) {

            balance += n;

        }

        public void Withdraw(double n) {

            balance -= n;

        }

        public double GetBalance() {

            return balance;

        }

    }

    class Program

    {

        static void Main()

        {

            BankAccount b = new BankAccount();

            b.Deposit(199);

            b.Withdraw(42);

            Console.WriteLine(b.GetBalance());

        }

    }