using System;

​

namespace PaintThis

{

    public abstract class Shape

    {

        public abstract void PaintThis();

    }

​

    public class Circle : Shape

    {

        public override void PaintThis()

        {

            Console.WriteLine("You painted: Circle");

        }

    }

​

    public class Triangle : Shape

    {

        public override void PaintThis()

        {

            Console.WriteLine("You painted: Triangle");

        }

    }

​

    public class Square : Shape

    {

        public override void PaintThis()

        {

            Console.WriteLine("You painted: Square");

        }

    }

​

    public class main_method

    {

        public static void Main()

        {

            Shape s;

            s = new Square();

            s.PaintThis();

            s = new Triangle();

            s.PaintThis();

            s = new Square();

            s.PaintThis();

        }

    }

}