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

Example Input: Healthy people can donate blood as often as once every _ weeks.
Example Output: eight

Example Input: Tapirs have hoofed toes, with four toes on the front feet and _ toes on the hind feet.
Example Output: three

Example Input: Insects have three body parts and _ legs.
Example Output:
six