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: type of sandwich 
Words: grilled cheese, french toast, outing, burger, club
Example Output: outing

Example Input: Category: social gathering 
Words: convention, club, discothek, hamburger, dance hall
Example Output: hamburger

Example Input: Category: aesthetic characteristic 
Words: fair, ghostly, trustworthy, light, tone
Example Output:
trustworthy