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: social gathering 
Words: club, bar, dance hall, discothek, roll
Example Output: roll

Example Input: Category: corporate 
Words: synergy, combined, concerted, resistant, firm
Example Output: resistant

Example Input: Category: shady activities 
Words: falsification, wrongful, rich, fudge, unlicensed
Example Output:
rich