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: fax, file, format, image, document
Example Output: fax

Example Input: brash, frank, bun, hot dog, grub
Example Output: brash

Example Input: comfortable, probation, fine, jail time, penalty
Example Output:
comfortable