using System;

class BaseClass 

{

    public void show1()

    {

        Console.WriteLine("this is a base class");

    }

    class derivedclass : BaseClass

    {

        public void show2()

        {

            Console.WriteLine("this is a derived class");

        }

    }

​

public class Program

{

    public static void Main()

    {

        derivedclass dc1 = new derivedclass();

        dc1.show1();

        dc1.show2();

    }

}

}

​

​

​