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: Background color can be a transition of ____ colors.
Example Output: two

Example Input: Tuberculosis develops in ____ stages.
Example Output: two

Example Input: Science is organized into ____ units in which inquiry and discovery are the focus.
Example Output:
four