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: elements 
Words: ban, fire, combustion, ground, flame
Example Output: ban

Example Input: Category: ocean 
Words: up to the moment, tide, current, jetstream, brine
Example Output: up to the moment

Example Input: Category: consumer product 
Words: content, activity, fearful, file, thing
Example Output:
fearful