using System;

public class Program

{

    public static void Main ()

    {

        //Console.WriteLine("Hello World");

        Object o = new B();

        ((B)o).Sod();    // A, B, mes A

    }

}

​

public class A

{

    public A ()

    {

        Console.WriteLine("A");

    }

    public virtual void Mes ()

    {

        Console.WriteLine("mes A");

    }

}

public class B : A

{

    public B ()

    {

        Console.WriteLine("B");

    }

    public override void Mes ()

    {

        Console.WriteLine("mes B");

    }

    public void Sod ()

    {

        base.Mes();

    }

}