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:
Multiplications are always ____ complemental.

Ex Output:
two


Ex Input:
Scullers use ____ oars, sweep oarsmen pull just one.

Ex Output:
two


Ex Input:
Wind erosion is a threat to soils in all ____ cropping systems and in pastures.

Ex Output:

four