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

Example Input: Most broaches have _ series of teeth.
Example Output: three

Example Input: Humans host _ species of louse, the head louse , the body louse and the pubic louse .
Example Output: three

Example Input: Compulsive Disorder affects about sixty- _ per ten thousand people in any given year.
Example Output:
nine