using System;

​

class Program

{

    static void Main(string[] args)

    {

        Car car1 = new Car();

        Car car2 = new ElectricCar();

​

        car1.OpenDoors();

        car2.OpenDoors();

    }

}

​

class Car

{

    public virtual void OpenDoors()

    {

        Console.WriteLine("Car doors opened");

    }

}

​

class ElectricCar : Car

{

    public override void OpenDoors()

    {

        Console.WriteLine("Electric car doors opened");

    }

}

​