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:
dump truck, tackle, crane, duck, mallet

Ex Output:
dump truck

Ex Input:
group, blt, french toast, hamburger, club

Ex Output:
group

Ex Input:
flutter, ant, soar, jog, fly

Ex Output:
ant