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

Input: Consider Input: Economists divide resources into _ basic categories of land, labor, capital, and management.

Output: four


Input: Consider Input: Young pandas mature very slowly and are almost _ months old before they are weened.

Output: six


Input: Consider Input: Titanium can exist in _ crystal forms.


Output: two