问C++计算总是打印出11

EN

cout << "Enter the digits one at a time, as if they were to be read from right to left." << endl;

cin >> digit_one;
cin >> digit_two;
cin >> digit_three;
cin >> digit_four;
cin >> digit_five;
cin >> digit_six;
cin >> digit_seven;
cin >> digit_eight;
cin >> digit_nine;

checksum = (11 - (((10, 9, 8, 7, 6, 5, 4, 3, 2) * (digit_one, digit_two, digit_three, digit_four, digit_five, digit_six, digit_seven, digit_eight, digit_nine)) % 11));

cout << "The checksum for this ISBN is " << checksum << endl;