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.

Ex Input:
Category: type of sandwich 
Words: open-faced, hero, club, discothek, hamburger

Ex Output:
discothek


Ex Input:
Category: aesthetic characteristic 
Words: cool, trustworthy, milky, fair, well

Ex Output:
trustworthy


Ex Input:
Category: mode of transportation 
Words: wave, spider, fly, flutter, bike

Ex Output:

spider