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.

Input: Consider Input: Category: elements 
Words: ice, fire, burn, let go, combustion

Output: let go


Input: Consider Input: Category: kitchenware 
Words: metal, glass, knifer, dish, cup

Output: metal


Input: Consider Input: Category: boats 
Words: box, crew, galley, deck, bridge


Output: box