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: outdoor sport activity 
Words: swim, wrestle, fish, canyoning, horse

Ex Output:
horse


Ex Input:
Category: animal 
Words: bus, leap, spider, run, fly

Ex Output:
bus


Ex Input:
Category: mode of transportation 
Words: bus, bike, fish, train, fly

Ex Output:

fish