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: aesthetic characteristic 
Words: comfortable, pretty, there, fine, classy
Example Output: comfortable

Example Input: Category: bird 
Words: goose, hoist, neck, swallow, crane
Example Output: hoist

Example Input: Category: physical activity 
Words: cold, swim, plummet, fall, exercise
Example Output:
cold