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: lifeline, knockout, deck, punch, tko
Example Output: lifeline

Example Input: doorstep, community, open-faced, club, hoagie
Example Output: community

Example Input: duck, pig, elephant, fall, sheep
Example Output:
fall