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: elements 
Words: pay, cool, combustion, air, fire

Output: pay


Input: Consider Input: Category: type of sandwich 
Words: dagwood, club, doorstep, hamburger, community

Output: community


Input: Consider Input: Category: physical property 
Words: fat, bulky, vitamin c, area, heavy


Output: vitamin c