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

Input: Consider Input: Oceanographers now understand the oceanic circulation much better than _ years ago.

Output: ten


Input: Consider Input: Armaments manufacturers use lithium to produce tritium in _ ways.

Output: two


Input: Consider Input: Cubs emerge from the den when they are four to _ months old.


Output: six