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: Female smokers enter menopause an average of ____ years earlier than nonsmokers.
Example Output: five

Example Input: Cells contain ____ families of small organic molecules.
Example Output: four

Example Input: All amphibians have ____ legs with the exception of caecilians, which are limbless.
Example Output:
four