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: ok, wispy, jail, prime, fine
Example Output: ok

Example Input: emotional upsets, emotional supports, down, ashamed, up
Example Output: up

Example Input: optimist, chill, relaxing, tropical, cool
Example Output:
optimist