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

Example Input: Category: poker 
Words: board, joker, deck, fold, apron
Example Output: apron

Example Input: Category: date status 
Words: current, blue, detestings, up to the moment, history
Example Output: blue

Example Input: Category: boats 
Words: caution, rudder, lifeline, sail, deck
Example Output:
caution