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:
fair, even, milky, ghostly, luke

Ex Output:
luke


Ex Input:
trap, kayak, bat, climbing, fish

Ex Output:
bat


Ex Input:
angular momentum, fat, calcium, brittleness, ugly

Ex Output:

calcium