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: poker 
Words: call, sail, deck, board, queen
Example Output: sail

Example Input: Category: emotional status 
Words: kind, down, sad, backward, emotionalities
Example Output: backward

Example Input: Category: physical property 
Words: big, large, fat, capacitance, big boned
Example Output:
big