Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.

Example Input: Most amphibians reach maturity at three or ____ years.
Example Output: four

Example Input: Erosion is divided into ____ main categories, water and wind.
Example Output: two

Example Input: International mail consists of ____ categories of mail.
Example Output:
three