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

int main()
{
	int quarters {0};
	int dimes {0};
	int nickels {0};
	int pennies {0};

	cout << "How many quarters do you have?\n";
	cin >> quarters;

	if (!cin) {
		cerr << "Sorry, that wasn't a valid whole number.\n";
		return EXIT_FAILURE;
	}

	if (quarters < 0) {
		cerr << "Sorry, you cannot have negative quarters.\n";
		return EXIT_FAILURE;
	}

	cout << "How may dimes do you have?\n";
	cin >> dimes;

	if (!cin){
		cerr << "Sorry, that wasn't a valid whole number.\n";
		return EXIT_FAILURE;
	}

	if (dimes < 0) {
		cerr << "Sorry, you cannot have negative dimes.\n";
		return EXIT_FAILURE;
	}

	cout << "How many nickels do you have?\n";
	cin >> nickels;

	if (!cin){
		cerr << "Sorry, that wasn't a valid whole number.\n";
		return EXIT_FAILURE;
	}

	if (nickels < 0){
		cerr << "Sorry, you cannot have negative nickels.\n";
		return EXIT_FAILURE;
	}

	cout << "How many pennies do you have?\n";
	cin >> pennies;

	if (!cin){
		cerr << "Sorry, that wasn't a valid whole number.\n";
		return EXIT_FAILURE;
	}

	if (pennies < 0){
		cerr << "Sorry, that wasn't a valid whole number.\n";
		return EXIT_FAILURE;
	}

	double money {quarters * 0.25 + dimes * 0.10 + nickels * 0.05 + pennies * 0.01};

	cout << "You have $" << money << ".\n";

	return EXIT_SUCCESS;

}