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: physical property 
Words: protein, pasty, fat, thin, angular momentum
Example Output: protein

Example Input: Category: boats 
Words: deck, gunwale, queen, lifeline, bridge
Example Output: queen

Example Input: Category: moral characteristic 
Words: fair, fine, well, alright, light
Example Output:
light