using System;

using System.Drawing;

​

abstract class Vehicle

{

    protected static Color s_color = Color.Green;

}

​

class Boat : Vehicle

{

    public Boat()

    {

        Console.WriteLine(s_color);

    }

}

​

class F117 : Vehicle

{

    public F117()

    {

        s_color = Color.Black;

        Console.WriteLine(s_color);

    }

}

public class Program

{

    public static void Main()

    {

        var boat = new Boat();

        var f117 = new F117();

        var boat2 = new Boat();

    }

}