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:
file, keys, document, fax, ram

Ex Output:
fax

Ex Input:
deck, stern, apron, blocking, caution

Ex Output:
stern

Ex Input:
running., close, right there, shut down, gated

Ex Output:
right there