Founder of the Tang Dynasty

Shen Yan, a versatile high school mathematics teacher, accidentally traveled to a soldier before the Xuanwu Gate Incident. By chance, he made great contributions and seized the opportunity to become the leader of the "Hundred Horsemen" who guarded the palace. How will he use his ability to become the foundation builder of the prosperous Tang Dynasty? In the Tang Dynasty, not only Taizong, but also a bug with modern thinking...