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

Ex Input:
Cockroaches require food every _ to ten days but mut take in water every ten days.

Ex Output:
seven

Ex Input:
Scientists use a characteristic to classify animals into _ groups.

Ex Output:
two

Ex Input:
Physical hunger is a physiological process that occurs every three to _ hours.

Ex Output:
four