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: Couples spend ____ billion dollars a year on infertility treatments.
Example Output: two

Example Input: Biennials require portions of ____ growing seasons to reproduce.
Example Output: two

Example Input: Sweet potatoes have ____ basic flesh types, dry or moist.
Example Output:
two