class Program
{
static void Main(string[] args)
{
origination o=new origination();
o.State = "on";
Memo m=new Memo(o.State);
o.showState();
o.State = "off";
o.showState();
o.BackOut(m);
o.showState();
Console.ReadKey();
}
}

public class origination
{
private string state;

public string State
{
get { return state; }
set { state = value; }
}

public void BackOut(Memo Memo)
{
State = Memo.State;
}

public void showState()
{
Console.WriteLine(State);
}

}

public class Memo
{
private string _state;

public string State
{
get { return _state; }

}

public Memo(string state)
{
this._state=state;
}
}