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: moral characteristic 
Words: light, unprejudiced, honorable, fair, unjust
Example Output: light

Example Input: Category: bird 
Words: crane, pelican, egret, hummingbird, upraise
Example Output: upraise

Example Input: Category: emotional status 
Words: down, unhappy, emotionalities, south, emotional state
Example Output:
south