namespace app{  

using System;

public abstract class Car{

    public int Wheels { get; }

    public double Speed { get; }

    public Car(int wheels, double speed){

        Wheels = wheels;

        Speed = speed;

    }

    public abstract void Write();   

}

public class BMW : Car{

    public BMW():base(4,120){}

    public override void Write(){

        Console.WriteLine($"Im BMW; Speed : {Speed}; Wheels : {Wheels}");

    }

}

​

    public class Program

    {

        public static void Main()

        {

            Car car = new BMW();

            car.Write();

        }

    }

}

​