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: location (proximity) 
Words: beside, closest, close, adjacent, shut
Example Output: shut

Example Input: Category: consumer product 
Words: fearful, content, merchandise, shop, program
Example Output: fearful

Example Input: Category: elements 
Words: retire, burn, heat, fire, ground
Example Output:
retire