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:
bike, flap, fly, walk, wave

Ex Output:
walk


Ex Input:
horse, trap, tiger, sea turtle, fish

Ex Output:
trap


Ex Input:
cupcake, fudge, tart, smear, cream

Ex Output:

smear