#include "exercise7_2.h"

int main() {
	Sales_data total;							// variable to hold the running sum
	if (read(cin, total)) {						// read the first transaction
		Sales_data trans;						// variable to hold data for the next transaction
		while (read(cin, trans)) {				// read the remaining transactions
			if (total.isbn() == trans.isbn())	// check the isbns
				total = total.combine(trans);	// update the running total
			else {
				print(cout, total) << endl;		// print the results
				total = trans;					// process the next book
			}
		}
		print(cout, total) << endl;				// print the last transaction
	}
	else {										// there was no input
		cerr << "No data?!" << endl;			// notify the user
	}

	system("pause");
	return 0;
}