Four.

Hmm... Your situation is dire. Yes, I suggest you to flee if you can. Green Book or Ada is too good to be lost. Plus, you don't seem to inflict enough damage to even significantly weaken it in reasonable time.

If you do hesitate to flee, I have some suggestions below:
>Sing a lullaby to the Greater Wing. Perhaps it will fall asleep.
>If singing isn't your forte, try a bedtime story.