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: fret, truss rod, emotional upsets, sad, worried
Example Output: truss rod

Example Input: Category: police punishment 
Words: acceptable, fine, hearing, jail time, probation
Example Output: acceptable

Example Input: Category: physical property 
Words: fat, big boned, chunky, heavy, calcium
Example Output:
calcium