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: mode of transportation 
Words: dive, fly, soar, jog, wave
Example Output: dive

Example Input: Category: social gathering 
Words: group, clan, team, club, doorstep
Example Output: doorstep

Example Input: Category: activity 
Words: dally, misuse, fritter, whittle, patty
Example Output:
patty