In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

Input: Consider Input: Plasma levels fall by about a half within three to _ hours.

Output: four


Input: Consider Input: Milk has _ essential nutrients for active bodies.

Output: nine


Input: Consider Input: Elephants have four molars, which are replaced five times, for a total of _ sets in a lifetime.


Output: six