using System;

public class Program

{

    public static void Main()

    {

        var @foo = new foo();

        var @bar = new bar();

        var neither = "Test";

        tst(@foo);

        tst(@bar);

        tst(neither);

    }

    public static void tst(Object x) {

        if (x.GetType() == typeof(foo))

            Console.WriteLine("Same type.");

        else if (x.GetType().IsAssignableTo(typeof(foo)))

            Console.WriteLine("Extends type.");

        else

            Console.WriteLine("Not related.");          

    }

    public class foo {}

    public class bar : foo {}

}