Chef and Storage rooms

Chef owns a storage chamber which he uses to store all his goods for his new business. A storage chamber is designed such that it consists of $N$ storage rooms that are placed in a square loop (the last room is just before the 1st room like a loop). For example, The room numbering starts from 1 which is placed at the bottom left and the last room (Room 12 in this case) lies to the right of Room 1