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: guitar part 
Words: truss rod, fret, neck, bored, strap lock
Example Output: bored

Example Input: Category: physical property 
Words: protein, pasty, fat, thin, angular momentum
Example Output: protein

Example Input: Category: food 
Words: hot dog, meat, loyalty, frank, provision
Example Output:
loyalty