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: animal 
Words: jog, jump, fish, fly, bats
Example Output: jog

Example Input: Category: physical activity 
Words: sprint, cow, duck, jog, squat
Example Output: cow

Example Input: Category: shady activities 
Words: fib, fudge, fix, cookies, falsehood
Example Output:
cookies