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: Ozone is formed of ____ atoms of oxygen.
Example Output: three

Example Input: ATMs are expensive machines with an average useful life of ____ to fifteen years.
Example Output: ten

Example Input: Sexual reproduction involves the union of cells from ____ parents.
Example Output:
two