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: Natural ytterbium is a mixture of ____ stable isotopes, with seven other unstable isotopes known.
Example Output: seven

Example Input: Cats have five toes on their front paws, but only ____ touch the ground when walking.
Example Output: four

Example Input: Females generally give birth by age ____ to eleven in captivity and thirteen to fifteen in the wild.
Example Output:
ten