So let's just review factorial a little bit. So if I were to say n factorial, that of course is going to be n times n minus, sorry, times n minus one times n minus two, n minus two, and I would just keep going down until I go to times one. So I would keep decrementing n until I get to one, and then I would multiply all of those things together. So for example, in all of this is review, if I were to say three factorial, that's going to be three times two times one. If I were to say two factorial, that's going to be two times one. One factorial, by that logic, well, I just keep decrementing until I get to one, but I don't even have to decrement here. I'm already at one, so I just multiply it one.