Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Ex Input:
townhome, mountain, studio, flat, apartment

Ex Output:
mountain

Ex Input:
probation, ticket, exquisite, suspension, fine

Ex Output:
exquisite

Ex Input:
concerted, united, hard, firm, common

Ex Output:
hard