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: fire, cool, water, ban, ice
Example Output: ban

Example Input: hull, galley, deck, lifeline, tko
Example Output: tko

Example Input: regular, popular, cadet, general, boring
Example Output:
cadet