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: format, file, support, text, download
Example Output: support

Example Input: hull, galley, deck, lifeline, tko
Example Output: tko

Example Input: bats, pounce, fly, train, run
Example Output:
train