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: animal 
Words: flutter, swim, ant, fly, bats
Example Output: flutter

Example Input: Category: computers 
Words: download, file, order office supplies, document, motherboard
Example Output: order office supplies

Example Input: Category: mode of transportation 
Words: fly, car, walk, swim, swim
Example Output:
swim