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: guitar part 
Words: fret, notes, emotional upsets, output cord, truss rod
Example Output: emotional upsets

Example Input: Category: boxing terminology 
Words: deck, gunwale, level, tko, jab
Example Output: gunwale

Example Input: Category: boxing terminology 
Words: deck, hull, fight, apron, tko
Example Output:
hull