Halloween has just happened, and all of the kids in the neighborhood have candy. 5 of them are standing in a circle comparing stashes, when one of them (kid 0) gets the idea to steal his neighbor's (kid 1's) candy. Kid 1 gets upset and runs away crying. Kid 2 sees kid 0 stealing from kid 1, thinks that he could do that too, and steals kid 3's candy. Kid 4 sees kid 2, and steals from kid 0, and so on and so forth until there's only one kid left. Given n children, find the index of the last kid remaining.