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

Example Input: Tall fescue produces the ____ diazaphenanthrene alkaloids, perlolidone and perloline.
Example Output: two

Example Input: Coral is a heterogeneous cluster built in ____ phases.
Example Output:
three