In Tang Dynasty, I’ve Been Expelled

Li Zheng was kicked out of a study hall in Chang'an because he was too stupid, and many people thought he was an abnormal person.

When he unraveled the Nine Chapters on Mathematics and cracked the Yinshan battlefield situation, everyone in Chang'an started looking for him...

Poetry, mathematics, medicine.

Li Zheng became famous in Chang'an.

The Five Noble Houses tried to recruit him, the emperor invited him, and the princes courted him.

Just as he was at the height of his glory, Li Zheng retreated from the world before everyone's eyes.

...

Fang Xuanling: "Li Zheng, the court situation is severe. Please come out of seclusion."

Li Chunfeng: "Li Zheng, I've given you the Tui Bei Tu. Please come out of seclusion."

Cheng Yaojin: "Li Zheng, the Turks and Tuyuhun are attacking again. Hurry and come out."

Li Shimin: "Li Zheng, it seems the Great Tang is about to fall. Please hurry and come out."

...

Li Zheng said calmly, "Stop yelling! My railway is almost finished."

This book is also known as I Really Don't Have Any Money Left to Protect the Great Tang Empire.