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

Example Input: Gravity is the weakest of all _ forces but unlike the others it has an unlimited range.
Example Output: four

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

Example Input: Pronghorn bucks have _ scent glands and does have six.
Example Output:
nine