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

Example Input: Tin exists in ____ allotropic forms.
Example Output: three

Example Input: Urine tests are really limited in that they only look for five to ____ substances.
Example Output:
nine