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: weather 
Words: even, tangle, mild, fair, 70
Example Output: even

Example Input: Category: shady activities 
Words: chocolate cake, invent, fudge, unwarranted, lie
Example Output:
chocolate cake