using System;

public class Program

{

    public static void Main()

    {

        var dat = new DataCont();

        string v = "0";

​

        dat.A = "1";

        dat.B = "2";

        dat.A = v = ("3");

        Console.WriteLine(v);

        Console.WriteLine(dat.A);

    }

}

​

public class Data

{

    public Data()

    {

    }

    public Data(string val)

    {

        Value = val;    

    }

    public string Value{get;set;}   

}

​

public class DataCont

{

    public DataCont() {}

​

    Data _A = new Data();

    public string A{get {return _A.Value; } set{ _A.Value = value; }}   

    Data _B = new Data();

    public string B{get {return _B.Value; } set{ _B.Value = value; }}   

}