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: Some countries require passports to be valid for ____ months after expiry of the visa.

Output: six


Input: Consider Input: Spermatogenesis creates ____ sperm of equal size.

Output: four


Input: Consider Input: Tidal currents are periodic with a net velocity of ____ over the tidal cycle.


Output: zero