using System;

class Class1

{

}

class Class2

{

}

public class IsTest

{

    public static void Test(object obj)

    {

        Class1 a;

        Class2 b;

        if (obj is Class1)

        {

            Console.WriteLine("obj is Class1");

            a = (Class1)obj;

        }

        else if (obj is Class2)

        {

            Console.WriteLine("obj is Class2");

            b = (Class2)obj;

        }

        else

        {

            Console.WriteLine("obj is neither Class1 nor Class2.");

        }

    }

    public static void Main()

    {

        Class1 c1 = new Class1();

        Class2 c2 = new Class2();

        Test(c1);

        Test(c3);

        Test("Passing String Value instead of class");

    }

}