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:
happy, substance, shop, tools, content

Ex Output:
happy


Ex Input:
ugly, absorption, vitamin c, fat, thin

Ex Output:
vitamin c


Ex Input:
flamingo, crane, mallet, winch, derrick

Ex Output:

winch