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: size, unjust, tone, fair, medium
Example Output: unjust

Example Input: heat, hire, burn, air, fire
Example Output: hire

Example Input: bulky, fiber, fat, brittleness, pasty
Example Output:
fiber