I Was Besieged by Zombies in the Song Dynasty

What should I do if I travel through time and become the emperor of the Southern Song Dynasty and the zombies besiege the city? Zhao Yun opened his eyes. Before the dragon robe was warm, the powerful Prime Minister Shi Miyuan sent a memorial to "Lian Meng to destroy the gold". What's worse - north of the Huaihe River, 100,000 zombies are gathering. The last emperor of the Jin Kingdom has become the king of corpses, and the Song Dynasty is the next dish. Empress Xie handed over an account book: "Get money first. Gunpowder, steam engines, royal companies - plant the fields before fighting." He looked north. That darkness is pressing in inch by inch