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: bird 
Words: digger, heron, crane, mallet, sandpiper

Output: digger


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

Output: heel


Input: Consider Input: Category: personal characteristic 
Words: hot, unflappalbe, cool, popular, classy


Output: hot