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: physical activity 
Words: run, jump, autumn, fall, swim
Example Output: autumn

Example Input: Category: mode of transportation 
Words: train, spider, wave, fly, drive
Example Output: spider

Example Input: Category: emotional status 
Words: loveful, emotional, down, miserable, downward
Example Output:
downward