Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Example Input: board, caution, fight, punch, deck
Example Output: board

Example Input: hardware, firewall, file, format, order office supplies
Example Output: order office supplies

Example Input: flat, level, house, round, hotel
Example Output:
level