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: physical property 
Words: thin, brittleness, heavy, angular momentum, fat

Ex Output:
heavy


Ex Input:
Category: bird 
Words: winch, swift, crane, hoist, ostrich

Ex Output:
winch


Ex Input:
Category: emotional status 
Words: emotional supports, melancholy, ground, down, kind

Ex Output:

ground