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

Ex Input:
Plasma levels fall by about a half within three to _ hours.

Ex Output:
four

Ex Input:
Diarrhea is an illness that kills _ and one-half million children per year.

Ex Output:
three

Ex Input:
Reality is confined to what the _ senses can perceive.

Ex Output:
five