Statement

During the winter William brings his coat at school, as everybody does. The only problem is that sometimes there are too many people in the classroom, and there's no space to put everybody's coat. The classroom has a coat hanger with N hooks, each of them able to hold 1 or 2 coat (one coat on top of the other). Any more than 2 coats on a single hook would cause it to break under the excessive weight. When students arrive, they usually try to find some empty hook to put their coat on and, if they don't find any, they will put their coat on top of another coat. If every hook has already 2 coats on it, then the student will just keep his coat (and will sweat a lot during the lecture). Today William managed to put his coat on the rack, however, after the end of the lecture, he didn't remember on which hook he had left it. Note that: (1) The coat might be under another coat (so it might be necessary to lift the other coat in order to see it)...