using System;

public class AAA

{

    public AAA()

    {

        Console.WriteLine("Normal AAA");

    }

    static AAA()

    {

        Console.WriteLine("Static AAA");

    }

    public static void method() // Can't be overriden

    {

        Console.WriteLine("Method AAA");

    }

}

​

public class BBB : AAA

{

    public BBB()

    {

        Console.WriteLine("Normal BBB");

    }

    static BBB()

    {

        Console.WriteLine("Static BBB");

    }

    public static new void method() // Method hiding

    {

        Console.WriteLine("Method BBB");

    }

}

​

public static class CCC : Object // Can't inherit anything but Object

{

    static CCC()

    {

        Console.WriteLine("Static CCC");

    }

    public static void method()

    {

        Console.WriteLine("Method CCC");

    }

}

​

public sealed class DDD : BBB // Can be instanciated

{

    public DDD()

    {

        Console.WriteLine("Normal DDD");

    }

    static DDD()

    {

        Console.WriteLine("Static DDD");

    }

    public static new void method()

    {

        Console.WriteLine("Method DDD");

    }

    public void method2()

    {

        Console.WriteLine("Method2 DDD");

    }

}

​

public class Program

{

    public static void Main()

    {       

        AAA.method();

        Console.WriteLine("-------------"); 

        CCC.method();

        Console.WriteLine("-------------");

        AAA a = new BBB();

        Console.WriteLine("-------------");

        DDD d = new DDD();

        d.method2();

        Console.WriteLine("-------------");

        DDD.method();

    }

}