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? Well, we could have, if no one sat down, we have five different people. Well, five different people could sit in seat one. Well, for each of these scenarios where one person has already sat in seat one, how many people could sit in seat two? Well, in each of these scenarios, if one person has sat down, there's four people left who haven't been seated, so four people could sit in seat two. So we have five times four scenarios where we have seated seats one and seat two. Now, for each of those 20 scenarios, how many people could sit in seat three?