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: outdoor sport activity
Words: kayak, raft, fish, canyoning, dolphin
Example Output: dolphin

Example Input: Category: type of rigidity
Words: tough, taut, rough, amalgamated, firm
Example Output: amalgamated

Example Input: Category: weather
Words: make the grade, raining, fair, luke, honorable
Example Output:
honorable