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:
goose, cow, bend, lion, duck

Ex Output:
bend


Ex Input:
fly, grasshopper, walk, waggle, train

Ex Output:
train


Ex Input:
sliding, unhappy, right, down, south

Ex Output:

unhappy