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: Teething begins for most babies around ____ to six months.
Example Output: four

Example Input: Some rusts produce up to ____ different spore forms.
Example Output: five

Example Input: Thrips pose ____ difficulties regarding chemical controls.
Example Output:
two