this source so that so this is like an optimal thing to do I roundabout way of answering the question of why use natural numbers but but I think the stack here is just a conceptual framework right we don't know the actual implementation we don't need stack yeah that's absolutely true with this we say it's a stack just because it has this property that every time we decode something it we just get the last thing that was encoded we don't get the first thing that I was encoded so we just call it a stack but but yeah you