And we showed it at the end of the last video. n factorial divided by n minus k factorial. It was n times n minus 1 times n minus 2, all the way to n minus k plus 1. If this was 7 over 7 minus 2 factorial, we would have 7 times 6, right? And 6 is 1 more than 7 minus 2. So that's where we got that. And we did that in the last video, if you're getting confused.