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: chocolate food 
Words: fudge, cream, replace, cookies, brownies
Example Output: replace

Example Input: Category: animal 
Words: bird, fish, fly, drive, eagle
Example Output: drive

Example Input: Category: aesthetic characteristic 
Words: hot, fine, classy, bright, happy
Example Output:
happy