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: moral characteristic 
Words: wiener, frank, integrity, loyalty, stern
Example Output: wiener

Example Input: Category: emotional status 
Words: fret, truss rod, emotional upsets, sad, worried
Example Output: truss rod

Example Input: Category: elements 
Words: air, combustion, ban, cool, fire
Example Output:
ban