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

Input: Consider Input: Humans are bipeds who stand between _ to six feet in height when fully grown.

Output: five

Input: Consider Input: Flatworms exhibit _ forms of life styles, free-living and parasitic.

Output: two

Input: Consider Input: Pathogens can enter our bodies through _ routes.
Output: four