using System;

public class Program

{

    public class TestClass

    {

        public int myNumber;

    }

    public static void Main()

    {

        var t1 = new TestClass();

        var t2 = t1;

        Console.WriteLine(t2.myNumber);

        t1.myNumber=2;

        Console.WriteLine(t2.myNumber);

        Console.WriteLine(t1.myNumber);

        t2.myNumber=5;

        Console.WriteLine(t2.myNumber);

        Console.WriteLine(t1.myNumber);

    }

}