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:
fire, hire, heat, inferno, earth

Ex Output:
hire


Ex Input:
firm, tough, solid, hard, streamline

Ex Output:
streamline


Ex Input:
file, folder, keys, prepare, program

Ex Output:

prepare