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: boats 
Words: hull, deck, rudder, check, lifeline
Example Output: check

Example Input: Category: food 
Words: sausage, frank, loyalty, cheese, pork
Example Output: loyalty

Example Input: Category: animal 
Words: cockroach, pounce, fly, fish, flutter
Example Output:
flutter