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

Example Input: Tapirs have hoofed toes, with four toes on the front feet and _ toes on the hind feet.
Example Output: three

Example Input: Anemone has _ vents.
Example Output: two

Example Input: Waves have _ mass and yet they carry energy as they travel through space.
Example Output:
no