Luigi is navigating a maze. He gets to a junction and has 3 directions he can go in. For each of these choices, he eventually gets to another junction where he has 6 choices of direction.
3 times 6 equals 18 so there are 18 possible paths right? There are 3 paths each with 6 other directions to go in after. So you can essentially group them into 3 groups with 6.
