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:
sail, bow, blind, dock, deck

Ex Output:
blind


Ex Input:
dump truck, tackle, crane, duck, mallet

Ex Output:
dump truck


Ex Input:
content, activity, books, file, sad

Ex Output:

sad