using System;

public class Program

{

    public static void Main()

    {

        //Rectangle rectangle = new Rectangle();

            //Rectangle square = new Square();

            ////Circle Cir = new Square();

            ////IShape shape = new IShape();

            //Circle circle = new Circle();

            //circle.Draw();

            //rectangle.Draw();

            //rectangle = new Square();

            //rectangle.Draw();

            //IShape shape = new Circle();

            //shape.Draw();

            //shape = new Rectangle();

            //shape.Draw();

​

            new Circle().Draw();

            //new IShape().Draw();

            Console.ReadLine();

    }

    public interface IShape

        {

            void Draw();

        }

​

        public class Circle : IShape

        {

            public void Draw()

            {

                Console.WriteLine("Draws Circle...");

            }

        }

​

        public class Rectangle : IShape

        {

            public virtual void Draw()

            {

                Console.WriteLine("Draws Rectangle...");

            }

        }

​

        public class Square : Rectangle

        {

            public override void Draw()

            {

                Console.WriteLine("Draws Square...");

            }

        }

}