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: military rank 
Words: general, fighter, normal, major, lieutenant

Ex Output:
normal


Ex Input:
Category: measurement unit 
Words: meter, inch, foot, heel, pound

Ex Output:
heel


Ex Input:
Category: construction 
Words: dump truck, hoist, crane, windlass, excavator

Ex Output:

hoist