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.

Ex Input:
Category: social gathering 
Words: place, bar, doorstep, club, outing

Ex Output:
doorstep


Ex Input:
Category: outdoor sport activity 
Words: whale, fish, raft, hiking, kayak

Ex Output:
whale


Ex Input:
Category: elements 
Words: heat, hire, burn, air, fire

Ex Output:

hire