#include <iostream>
using namespace std;

double const G = 6.673E-8;

double gravity(double mass1_par, double mass2_par, double distance_par);

int main()

{
	double mass_1, mass_2, distance;
	char again;
	double force;
	do
	{
		cout << "What is the mass of the first object in grams?" << endl;
		cin >> mass_1;
		cout << "The first object is " << mass_1 << " g." << endl;
		cout << "What is the mass of the second object in grams?" << endl;
		cin >> mass_2;
		cout << "The second object is " << mass_2 << " g." << endl;
		cout << "What is the distance between the two objects in centimeters?" << endl;
		cin >> distance;
		cout << "The distance between the two obejects is " << distance << " cm." << endl;
		force = gravity(mass_1, mass_2, distance);
		cout << "The force due to gravity is " << force << " dyne." << endl;
		cout << " Would you like to make another calculation? Y= yes N= no" << endl;
		cin >> again;
	} while ((again == 'y') || (again == 'Y'));
	return 0;
}

double gravity(double mass1_par, double mass2_par, double distance_par)
{
	return ((G * mass1_par * mass2_par) / (distance_par*distance_par));
}