using System;

class class1

{

}

class class2

{

}

public class IsTest

{

public static void Test (object o)

{

class1 a;

class2 b;

if (o is class1)

{

Console.WriteLine("0 is class1");

a=(class1)o;

}

else if (o is class2)

{

Console.WriteLine("o is class2");

b=(class2)o;

}

else

{

Console.WriteLine("o is neither class1 nor class2");

}

}

public static void Main()

{

class1 c1=new class1();

class2 c2=new class2();

Test(c1);

Test(c2);

Test("a string");

}

}