#include
#include "Sales_item.h"
int main(){
Sales_item item, addItem;
std::cout << std::endl;
std::cin >> item;
while (std::cin >> addItem)
item += addItem;
std::cout<<"The sum of this books is "<<item<<std::endl;
return 0;
}
PS:鄙人C++之极品菜鸟,请使劲喷。