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: type of sandwich 
Words: club, open-faced, convention, doorstep, roll
Example Output: convention

Example Input: Category: physical activity 
Words: bend, jog, get down, duck, pig
Example Output: pig

Example Input: Category: card games 
Words: slapjack, spades, whisky, gin, blackjack
Example Output:
whisky