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 rigidity 
Words: solid, leverage, hard, unbending, firm

Ex Output:
leverage


Ex Input:
Category: animal 
Words: waggle, drive, fly, bee, dive

Ex Output:
drive


Ex Input:
Category: aesthetic characteristic 
Words: cool, fair, luke, level, milky

Ex Output:

luke