So let's say that we only have three chairs. So we have chair one, we have chair two, and we have chair three. So how many ways can you have five people where only three of them are going to sit down in these three chairs? And we care which chair they sit in, and I encourage you to pause the video and think about it. So I am assuming you have had your go at it. So let's use the same logic. So how many, if we seat them in order, we might as well, how many different people, if we haven't sat anyone yet, how many different people could sit in seat one?