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

Example Input: Woodchucks can dig up to three entrances to _ den.
Example Output: one

Example Input: Most amphibians reach maturity at _ or four years.
Example Output: three

Example Input: Basidia produce _ spores at the end of microscopic spines called sterigma.
Example Output:
four