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: air, fire, hire, ban, promote
Example Output: air

Example Input: concrete pourer, winch, excavator, hoist, crane
Example Output: hoist

Example Input: luke, fair, variety, tone, well
Example Output:
luke