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.

Input: Consider Input: Nitric oxide serves ____ main functions in the body.

Output: three


Input: Consider Input: Eye contact is important for ____ reasons.

Output: two


Input: Consider Input: Female manatees begin reproducing at about ____ years of age.


Output: four