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: lower, backward, down, falling, shameful
Example Output: shameful

Example Input: general, boring, soldier, ubiquitous, average
Example Output: soldier

Example Input: history, sea, postponed, do tests, current
Example Output:
sea