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

Example Input: Pups consume an average of _ liters of milk a day .
Example Output: eight

Example Input: Melanocytes are dendritic and are distributed roughly _ per six basal cells.
Example Output: one

Example Input: Caterpillars have _ types of legs which perform different functions.
Example Output:
two