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: Photons have no mass and ____ electrical charge.
Example Output: no

Example Input: Ground squirrels have a single litter a year that averages from ____ to nine young.
Example Output: four

Example Input: Pups stay in the den for about ____ weeks and then begin traveling short distances with adults.
Example Output:
six