using System;

​

interface SportsCar {

void WhatAreYou();

}

interface GermanCar {

void WhatAreYou();

}

abstract class Car {

public virtual void WhatAreYou(){Console.WriteLine("I am a Car"); }

}

abstract class Golf : GermanCar{

public virtual void WhatAreYou() {Console.WriteLine("I am a Golf"); }

}

class GolfGTI : Golf, SportsCar {

public override void WhatAreYou() {Console.WriteLine("I am a Golf GTI"); }

}

abstract class Opel : Car, GermanCar {

public override void WhatAreYou(){Console.WriteLine("I am an Opel"); }

}

class Manta : Opel, SportsCar {

 public new void WhatAreYou() {Console.WriteLine("eeh du, echt cool"); }

}

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Car car1 = new Manta();

        Golf car2 = new GolfGTI();

        ((Opel)car1).WhatAreYou();

        ((GolfGTI)car2).WhatAreYou();

        ((Manta)car1).WhatAreYou();

        ((SportsCar)car1).WhatAreYou();

        car2.WhatAreYou();

        car1.WhatAreYou();

    }

}