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: All insects have _ pairs of legs and adult wings.

Output: three


Input: Consider Input: Crows begin to fly sufficiently to be released at _ weeks or so.


Output: eight