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

Example Input: Category: direction 
Words: up, down, sliding, shameful, right
Example Output: shameful

Example Input: Category: physical property 
Words: brittleness, protein, bulky, skinny, fat
Example Output:
protein