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: emotional status 
Words: kind, down, sad, backward, emotionalities
Example Output: backward

Example Input: Category: shady activities 
Words: invent, smuggled, smear, fudge, pie
Example Output: pie

Example Input: Category: elements 
Words: fire, heat, air, inferno, pay
Example Output:
pay