They've mastered the crossbow. They're using mercenaries and cavalries and it's really awesome warfare, but there's no real centralized authority to be heard of. So we hope you guys know something about early Chinese civilization, the geography, the beginning of the dynasty, the oracle bones. You've got to remember the oracle bones. So I'm going to end it here, guys. We hope your brain is nice and big and bubbly. And I'm going to say it because I say it at the end of every video lecture because I know it's true with all my heart.