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: food 
Words: sausage, loyalty, grub, frank, provision
Example Output: loyalty

Example Input: Category: aesthetic characteristic 
Words: trustworthy, variety, tone, ghostly, fair
Example Output: trustworthy

Example Input: Category: employment activity 
Words: recruit, fire, promote, air, replace
Example Output:
air