Then n is 5, 5 minus 2, you had 3 possibilities for the last head. This actually works. This is the number of spots or the number of ways that we can put 3 heads into 5 different possible buckets. Just like the last video, we don't want to over count things, because we don't care about the order. We don't want to differentiate one ordering of heads. I'm just going to use these letters to differentiate the different heads. We don't want to differentiate this from this.