#include <iostream>
#include <cstdlib>
#include <chrono>
#include <ctime>
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)};

	const int hour {p->tm_hour};

	if (hour < 6 ) {
		cout << "Go to bed!\n";
	}
	else if (hour <= 12 ) {
		cout << "Good morning!\n";
	}
	else if (hour <= 17 ) {
		cout << "Good afternoon!\n";
	}
	else if (hour <= 20 ) {
		cout << "Good evening!\n";
	}
	else {
		cout << "Good night!\n";
	}
	return EXIT_SUCCESS;
}