using System;

public abstract class Shape

{

public abstract string GetShape();

}

​

public class Triangle:Shape

{

public override string GetShape()

{

return "Triangle";

}

}

​

public class Circle:Shape

{

public override string GetShape()

{

return "Circle";

}

}

​

public class Program

{

    public static void Main()

    {

        Shape cirleShape= new Circle();

        Console.WriteLine(cirleShape.GetShape());

        Shape triangleShape=new Triangle();

        Console.WriteLine(triangleShape.GetShape());

​

    }

}