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.

Ex Input:
Category: animal 
Words: cockroach, leap, drive, swim, fly

Ex Output:
drive


Ex Input:
Category: animal 
Words: walk, flap, fish, fly, bats

Ex Output:
flap


Ex Input:
Category: boxing terminology 
Words: tko, fight, dock, deck, level

Ex Output:

dock