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.

Input: Consider Input: Category: type of rigidity 
Words: solid, leverage, hard, unbending, firm

Output: leverage


Input: Consider Input: Category: police punishment 
Words: ticket, comfortable, prime, custody, fine

Output: comfortable


Input: Consider Input: Category: moral characteristic 
Words: impartial, fair, just, tone, unprejudiced


Output: tone