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.

Ex Input:
Erosion is divided into ____ main categories, water and wind.

Ex Output:
two


Ex Input:
Bullying is most severe in grades ____ to nine.

Ex Output:
seven


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

Ex Output:

four