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:
heron, davit, egret, derrick, crane

Ex Output:
davit

Ex Input:
hoist, crane, excavator, winch, windlass

Ex Output:
hoist

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

Ex Output:
data sets