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: jail, probation, fine, classy, firstrate
Example Output: classy

Example Input: fiber, big boned, protein, carbs, fat
Example Output: big boned

Example Input: ground, down, forward, unhappy, flat
Example Output:
unhappy