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: police punishment 
Words: prison, fine, calm, money, suspension
Example Output: calm

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

Example Input: Category: aesthetic characteristic 
Words: well, fine, neat, beautiful, level
Example Output:
well