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: happy, substance, shop, tools, content
Example Output: happy

Example Input: dally, misuse, fritter, whittle, patty
Example Output: patty

Example Input: hard, firm, united, ceo, private
Example Output:
hard