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: convention, club, discothek, hamburger, dance hall
Example Output: hamburger

Example Input: Category: secretary duty 
Words: file, organize, schedule appointments, answer calls, program
Example Output: program

Example Input: Category: direction 
Words: flat, descending, disgusted, down, right
Example Output:
disgusted