And I know, based on the reasoning, the conceptual reasoning of this, this doesn't make any sense. But since we've already been exposed a little bit to permutations, I'll show you why this is a useful concept, especially in the world of permutations and combinations, which is, frankly, where factorial shows up the most. I would say that most of the cases that I've ever seen, factorial in anything, has been in the situations of permutations and combinations. And in a few other things, but mainly permutations and combinations. So let's review a little bit. We've said that, hey, you know, if we have n things and we want to figure out the number of ways to permute them into k spaces, it's going to be, it's going to be n factorial over n minus, over n minus k factorial. Now we've also said that if we had, if we had n things that we want to permute into n places, well this really should just be n factorial.