In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

Ex Input:
Miniature cattle are classified in _ categories as measured by height at the hip.

Ex Output:
three


Ex Input:
Retinoic acid regulates oral epithelial differentiation by _ mechanisms.

Ex Output:
two


Ex Input:
Trees begin to form fruiting buds at around _ years of age.

Ex Output:

three