The Fortress City of the Apocalypse

Su Chen, who had struggled to survive in the apocalypse for 30 years, made a mistake and was deeply surrounded by zombies. However, he did not die and returned to three days before the cataclysm broke out. This time, he is 30 years ahead of everyone. He can be one step ahead, obtain the items he desired in his previous life, build a huge city in a cold place, and find a glimmer of hope in this apocalyptic world.