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 activity 
Words: trip, jump, fall, equinox, exercise

Ex Output:
equinox


Ex Input:
Category: construction 
Words: hoist, tackle, digger, excavator, crane

Ex Output:
tackle


Ex Input:
Category: boats 
Words: hull, deck, rudder, check, lifeline

Ex Output:

check