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:
elephant, duck, sprint, dog, lion

Ex Output:
sprint


Ex Input:
kind, down, sad, backward, emotionalities

Ex Output:
backward


Ex Input:
ok, clime, cold, brisk, fair

Ex Output:

ok