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: animal 
Words: ant, walk, bike, fly, dangle

Ex Output:
bike


Ex Input:
Category: type of rigidity 
Words: tough, taut, rough, amalgamated, firm

Ex Output:
amalgamated


Ex Input:
Category: ocean 
Words: current, dastards, tide, signal, drink

Ex Output:

dastards