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: type of sandwich 
Words: hoagie, burger, hamburger, club, discothek
Example Output: discothek

Example Input: Category: animal 
Words: fly, dangle, bee, jump, flap
Example Output: flap

Example Input: Category: personal characteristic 
Words: mild, cool, ethical, unflappalbe, level
Example Output:
mild