using System;

public class Program

{

    public static void Main()

    {

        childclass obj = new childclass();

        obj.method();

        bassclass obj1 = new childclass();

        obj1.method();

    }

    class bassclass

    {

        public virtual void method(){

            Console.WriteLine("this is bass class");

        }

    }

    class childclass : bassclass

    {

        public override void method()

        {

            base.method();

            Console.WriteLine("this is child class");

        }

    }

}