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, cool, water, ban, ice

Ex Output:
ban


Ex Input:
current, wave, whirlpool, sea, data sets

Ex Output:
data sets


Ex Input:
train, spider, wave, fly, drive

Ex Output:

spider