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: body part 
Words: elbow, foot, knee, inch, hand
Example Output: inch

Example Input: Category: boxing terminology 
Words: deck, tko, box, glove, sail
Example Output: sail

Example Input: Category: police punishment 
Words: ticket, fine, pretty, jail, suspension
Example Output:
pretty