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:
ugly, absorption, vitamin c, fat, thin

Ex Output:
vitamin c


Ex Input:
pie, fried, misuse, fritter, cake

Ex Output:
misuse


Ex Input:
water, air, instruct, heat, fire

Ex Output:

instruct