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: Sexual maturity occurs at ____ to four years for females and four to five years for males.
Example Output: three

Example Input: Variable stars fall into ____ major physical classifications.
Example Output: four

Example Input: Pets also track in pollen, and ____ out of every ten people is allergic to cat or dog dander.
Example Output:
one