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: boxing terminology 
Words: canvas, tko, deck, joker, fight
Example Output: joker

Example Input: Category: animal 
Words: flutter, fly, bats, eagle, pounce
Example Output: flutter

Example Input: Category: weather 
Words: sunny, clime, make the grade, fair, size
Example Output:
size