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

Ex Input:
Most people see the world through _ types of visual-receptor cells.

Ex Output:
four


Ex Input:
Cancer can start in any of the _ sections or where the colon ends in the rectum.

Ex Output:
four


Ex Input:
Skunks see well up to only about _ feet.

Ex Output:

three