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: boats 
Words: deck, call, galley, bridge, stern
Example Output: call

Example Input: Category: employment activity 
Words: pay, instruct, heat, fire, scold
Example Output: heat

Example Input: Category: police punishment 
Words: prime, penalty, fine, comfortable, prison
Example Output:
comfortable