I work in sales in Douluo

Introduction: Traveling through Douluo, the system actually asked me to open a supermarket?The first day of opening the supermarket: Tang San bought ten bottles of mineral water. The second day of opening the supermarket: Tang Hao bought one hundred bottles of mineral water. The third day of opening the supermarket: Old Jack bought ten bottles of mineral water... The nth day of opening the supermarket. : Emperor Xue Ye bought 1000 million bottles of mineral water and opened a supermarket on the n+n day: Emperor Xue Ye begged me to sell him a batch of shotguns and opened a supermarket on the n+n+n day: God Realm asked me to open it quickly Branch [Well, the introduction is not very good, but the content is not bad. 】