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

Input: Consider Input: Pelycosaurs are a paraphyletic group of _ primitive families of synapsids.

Output: six


Input: Consider Input: Education wastes about _ thirds of the talent of society.

Output: two


Input: Consider Input: Peccaries have a complex stomach that contains _ compartments.


Output: four