Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Example Input: Category: emotional status 
Words: nervous, frustrated, fret, jack, concerned
Example Output: jack

Example Input: Category: military rank 
Words: sargent, ordinary, captain, colonel, general
Example Output: ordinary

Example Input: Category: animal 
Words: fish, whale, hiking, goat, dog
Example Output:
hiking