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.

Example Input: bow, fold, hull, deck, head
Example Output: fold

Example Input: cake, fudge, rich, invent, cream
Example Output: invent

Example Input: lion, cow, duck, cat, stoop
Example Output:
stoop