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.

Ex Input:
current, flow, history, signal, jetstream

Ex Output:
history


Ex Input:
size, equitable, fair, alright, fine

Ex Output:
size


Ex Input:
lower, forward, emotional state, south, down

Ex Output:

emotional state