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

Example Input: Temperatures occasionally fall below _ but only last a very short time.
Example Output: zero

Example Input: Nuclear envelopes form around the _ new nuclei.
Example Output: two

Example Input: Porcupines have _ toes on their front paws and five on their rear paws.
Example Output:
four