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: baby animals 
Words: bambi, cub, doe, lust, fawn
Example Output: lust

Example Input: Category: guitar part 
Words: fret, concerned, jack, notes, amp
Example Output: concerned

Example Input: Category: direction 
Words: forward, backward, sad, down, sliding
Example Output:
sad