算出下期首尾和值方法简介：Baidi City only existed in Baidi's mouth, saying that he came from an ancient city, but Jianghu had never had such power, so people in the Jianghu named it Baidi City.
Baidi City only existed in Baidi's mouth, saying that he came from an ancient city, but Jianghu had never had such power, so people in the Jianghu named it Baidi City.
