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: animal 
Words: stingray, horse, iguana, wrestle, fish
Example Output: wrestle

Example Input: Category: measurement unit 
Words: ounce, foot, kilometer, milimeter, heel
Example Output: heel

Example Input: Category: shady activities 
Words: fudge, unwarranted, smuggled, replace, pudding
Example Output:
pudding