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.

Q: summer, roll, plummet, fall, exercise

A: summer
****
Q: level, tone, fair, impartial, milky

A: impartial
****
Q: well, detached, happy, fine, pretty

A:
pretty
****