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: nutritional value 
Words: iron, heavy, vitamin c, fat, brittleness
Example Output: brittleness

Example Input: Category: bird 
Words: dump truck, pelican, goose, crane, derrick
Example Output: dump truck

Example Input: Category: animal 
Words: dolphin, dog, fish, shark, raft
Example Output:
raft