#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
	double distanceMiles{0.0};
	double averageSpeed{0.0};

	cout << "Enter total trip distance in miles:\n";
	if(!(cin >> distanceMiles)){
		cerr << "Sorry, that wasn't a number.\n";
		return EXIT_FAILURE;
	}

	cout << "Enter your average speed in miles per hour:\n";
	if(!(cin >> averageSpeed)){
		cerr << "Sorry, that wasn't a number.\n";
		return EXIT_FAILURE;
	}

	const double hours{distanceMiles / averageSpeed};
	cout << "Estimated travel time: " << hours << " hours.\n";

	return EXIT_SUCCESS;
}