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: Gibberellins are diterpenoids derived from four isoprenoid units forming a system of ____ rings.

Output: four

Input: Consider Input: Electric power means no gas or oil to spill, and ____ pollution in the air.

Output: no

Input: Consider Input: Scallops have a shelf life of two to ____ days.
Output: three