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: blow, waste away, fritter, dally, croquet
Example Output: croquet

Example Input: order office supplies, sort mail, file, program, type
Example Output: program

Example Input: fly, train, cockroach, beetle, dive
Example Output:
train