#include <iostream>
#include <cstdlib>
#include <chrono>   //for class system_clock
#include <ctime>    //for the function localtime
using namespace std;

int main()
{
	const auto now {chrono::system_clock::now()};
	const time_t t {chrono::system_clock::to_time_t(now)};
        const tm *const p {localtime(&t)};

        //Get the current hour of the day (0 to 23 inclusive).
        const int hour {p->tm_hour};

        if (hour >= 0  && hour < 12) {
                cout << "Good morning!\n";
        } else if (hour >= 12 && hour < 18) {
                cout << "Good afternoon!\n";
        } else {
                cout << "Good evening!\n";
        }

        return EXIT_SUCCESS;
}