商品销售管理系统

计算上个月每个人每种产品的销售额。

按销售额对销售员进行排序，输出排序结果（销售员代号）

统计每种产品的总销售额，对这些产品按从高到底的顺序，输出排序结果（需输出产品的代号和销售额）

-Goods sales management system to calculate each month' s sales of each product. Sales by sales staff to sort out sort results (Seller code) Statistics for each product' s total sales of these products according to the order from high in the end, the output sort results (take out the product code and sales)