#include <iostream>
using namespace std;

bool is_leap_year(const int year);

int main()
{
	int year = 0;
	int day = 0;
	bool day_valid = false;

	while (!year)
	{
		cout << "Enter the year: ";
		cin >> year;
		if (year < 0 || year > 9999)
		{
			cout << "That's not a valid year!" << endl;
			year = 0;
		}
	}

	while (!day_valid)
	{
		cout << "Enter the day of the week of January 1st, using 0 through 6." << endl;
		cout << "(0 = Sun, 1 = Mon, 2 = Tue, 3 = Wed, 4 = Thu, 5 Fri, 6 = Sat)" << endl;
		cin >> day;
		if (day < 0 || day > 6)
			cout << "That's not a valid day! Must be between 0 and 6!" << endl;
		else
			day_valid = true;
	}

}

bool is_leap_year(const int year)
{
	if (year%4==0)
	{
		if (year % 100 == 0 && year % 400 != 0)
			return false;
		return true;
	}
	return false;
}