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 activity 
Words: tumble, summer, fall, bend, lift
Example Output: summer

Example Input: Category: aesthetic characteristic 
Words: 70, variety, color, fair, light
Example Output: 70

Example Input: Category: moral characteristic 
Words: well, luke, balanced, unprejudiced, fair
Example Output:
luke