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:
Fire occurs any time ____ elements are present - fuel, heat, oxygen and the chemical chain reaction.

Ex Output:
four


Ex Input:
Tin exists in ____ allotropic forms.

Ex Output:
three


Ex Input:
All vertebrates have ____ homeobox complexes, each on separate chromosomes.

Ex Output:

four