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: boxing terminology 
Words: apron, punch, deck, canvas, call

Ex Output:
call


Ex Input:
Category: animal 
Words: fly, dangle, bee, jump, flap

Ex Output:
flap


Ex Input:
Category: type of rigidity 
Words: tough, rough, resistant, firm, combined

Ex Output:

combined