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: elements 
Words: ice, fire, burn, let go, combustion

Ex Output:
let go


Ex Input:
Category: activity 
Words: fried, spend, whittle, waste, fritter

Ex Output:
fried


Ex Input:
Category: window material 
Words: coating, metal, woodwork, plate, glass

Ex Output:

plate