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:
running., close, bordering, nearer, touching

Ex Output:
running.


Ex Input:
well, money, fine, decent, acceptable

Ex Output:

money