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.

Example Input: current, wave, whirlpool, sea, data sets
Example Output: data sets

Example Input: fat, calories, thin, salt, vitamin c
Example Output: thin

Example Input: crew, board, deck, rudder, hull
Example Output:
board