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: aesthetic characteristic 
Words: fair, unprejudiced, level, tone, milky
Example Output: unprejudiced

Example Input: Category: ocean 
Words: current, wave, whirlpool, sea, data sets
Example Output: data sets

Example Input: Category: physical property 
Words: obese, large, fat, protein, brittleness
Example Output:
protein