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: windlass, excavator, crane, hummingbird, steam roller
Example Output: hummingbird

Example Input: fighter, boring, popular, standard, general
Example Output: fighter

Example Input: burn, cool, combustion, fire, remove
Example Output:
remove