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: milky, fair, ok, loyal, unprejudiced
Example Output: milky

Example Input: Category: employment activity 
Words: sack, inferno, promote, empower, fire
Example Output: inferno

Example Input: Category: bird 
Words: tackle, dump truck, davit, crane, ostrich
Example Output:
dump truck