Three Kingdoms Punk

As the gears clicked, the numbers on the wheel gradually became fixed, "one four one four two one three". Zhang Fei stared wide-eyed and asked Li Goudan, "What's the use of this?" Guan Yudan closed his eyes slightly, stroking his long beard and said nothing. Liu Bei looked at Li Goudan with affectionate and expectant eyes, "Would you like to explain it to us?" Li Goudan smiled lightly and said, "The difference engine is very useful!"