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

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

Example Input: Some dads can handle two or _ children.
Example Output: three

Example Input: Chimpanzees give birth to a single infant approximately every _ years.
Example Output:
five