The product manager died suddenly and was transported to a prison in the Northern Song Dynasty. There was no system and no grandfather. He relied on elementary school mathematics to expose the corruption of the prison boss in exchange for his first meal of meat and wine. From distilled spirits to double-entry accounting, from military bonds to border posts, he used modern knowledge to weave a web in the prosperous age that was about to collapse - saving himself and a group of people who should not be crushed by the times. The girl next to her from Yanzhou has three knives at her waist and an account written by her father in his hand.
