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: truss rod, emotional supports, emotional upsets, emotionalities, fret
Example Output: truss rod

Example Input: firm, tough, solid, hard, streamline
Example Output: streamline

Example Input: lifeline, deck, galley, bridge, fold
Example Output:
fold