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

Example Input: Transitional milk is secreted between about four days and _ days postpartum.
Example Output: ten

Example Input: Rodents have _ toes on their front feet and five on the hind feet.
Example Output: four

Example Input: Masturbation can get really old after _ or seven years.
Example Output:
six