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

Example Input: Diatoms are in _ shells and make the water brown.
Example Output: two

Example Input: Sprouts can grow as much as _ feet per year.
Example Output: six

Example Input: Mitosis ends when a B spermatogonium yields _ primary spermatocytes.
Example Output:
two