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

Input: Consider Input: Liquid crystals lack the full _ dimensional position and orientation order of ordinary crystals.

Output: three


Input: Consider Input: Carbon dioxide accounts for _ fourths of the predicted increase in the greenhouse effect.

Output: three


Input: Consider Input: Infertility affects about _ in six couples of child-bearing age.


Output: one