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: secretary duty 
Words: answer calls, image, organize, file, correspondence
Example Output: image

Example Input: Category: shady activities 
Words: fudge, banned, brownie, unwarranted, fib
Example Output: brownie

Example Input: Category: computers 
Words: software, sort mail, folder, file, keys
Example Output:
sort mail