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: employment activity 
Words: fire, hire, ground, pay, retire
Example Output: ground

Example Input: Category: bird 
Words: digger, heron, crane, mallet, sandpiper
Example Output: digger

Example Input: Category: computers 
Words: file, ram, image, organize, hardware
Example Output:
organize