using System;

public class Program

{

    struct Data

    {

        public int v;

    }

    public static void Main()

    {

        Data d;

        d.v = 42;

        Console.WriteLine(d.v);

        var d2 = d;

        d.v = 43;

        Console.WriteLine(d.v);

        Console.WriteLine(d2.v);

    }

}