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: window material 
Words: glass, spyhole, handle, coating, knive
Example Output: knive

Example Input: Category: shady activities 
Words: unwarranted, mangle, cream, loosen, fudge
Example Output: cream

Example Input: Category: personal characteristic 
Words: funny, persistent, positive, cool, warm
Example Output:
warm