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: inlays, concerned, string, notes, fret
Example Output: concerned

Example Input: Category: police punishment 
Words: ticket, comfortable, prime, custody, fine
Example Output: comfortable

Example Input: Category: animal 
Words: iguana, fish, kayak, mice, stingray
Example Output:
kayak