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: employment activity 
Words: recruit, replace, sack, heat, fire
Example Output: heat

Example Input: Category: accomodation 
Words: elevation, level, round, flat, townhome
Example Output: elevation

Example Input: Category: aesthetic characteristic 
Words: fair, pale, even, size, unjust
Example Output:
unjust