#include
using namespace std;

int main()
{

const double COMM_RATE = 0.1;
double sales = 0.0;
double commission = 0.0;

cout << "Enter a sales amount (negative number or 0 to end): ";
cin >> sales;
while (sales < 0.0)
{
commission = sales * COMM_RATE;
cout << "Commission: $" << commission << endl;
}




return 0;
}