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

Ex Output:
tropical


Ex Input:
Category: type of rigidity 
Words: solid, leverage, hard, unbending, firm

Ex Output:
leverage


Ex Input:
Category: baby animals 
Words: fawn, calf, expression, kitten, bambi

Ex Output:

expression