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: personal characteristic 
Words: ethical, tropical, unflappalbe, cool, optimist
Example Output: tropical

Example Input: Category: social gathering 
Words: meeting, cinema, club, group, submarine
Example Output: submarine

Example Input: Category: food 
Words: provision, frank, hot dog, goodies, harsh
Example Output:
harsh

