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: social gathering 
Words: club, bar, dance hall, discothek, roll
Example Output: roll

Example Input: Category: outdoor sport activity 
Words: hunt, row, wrestle, fish, hamster
Example Output: hamster

Example Input: Category: moral characteristic 
Words: honesty, fortitude, harsh, frank, bun
Example Output:
bun