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:
streamline, sustainability, private, firm, stiff

Ex Output:
stiff


Ex Input:
sergeant, general, standard, plain, ordinary

Ex Output:
sergeant


Ex Input:
stern, pork, entree, frank, weenie

Ex Output:

stern