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: Industrial halocarbons are effective ozone-depleters for ____ reasons.
Example Output: two

Example Input: Light chains exist in ____ classes, lambda and kappa.
Example Output: two

Example Input: Biennial weeds require ____ years to complete their life cycle.
Example Output:
two