I Am Not the Xiongnu, but Also the Han Emperor

After Liu Yan woke up, he got three pieces of good news. First, he traveled to the Han Dynasty. Second, his surname is Liu. Third, the Han Dynasty regained Chang'an. But there's also bad news. Today's surname is Liu Mingcong. This Han is the Han of Hu Han. To make matters worse, ten days later, he would have to hand over 1,200 shi of military rations.