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: ecstatic, specialty, substance, content, merchandise
Example Output: ecstatic

Example Input: group, blt, french toast, hamburger, club
Example Output: group

Example Input: rudder, bow, pack, crew, deck
Example Output:
pack