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: belated, jetstream, detestings, current, delayed
Example Output: jetstream

Example Input: streamline, sustainability, private, firm, stiff
Example Output: stiff

Example Input: ethical, unruffled, calm, cool, chill
Example Output:
chill