#include <iostream>
#include <iomanip>
#include <sstream>

using namespace std;

void dayNight(string ss)
{
    int h, m, s;
    char c;
    istringstream(ss) >> h >>c >> m >> c >> s;

    if (h >=21 || h <= 5) cout << "Ночь\n"; else cout << "День\n";
}


int main(int argc, char * argv[])
{
    dayNight("13:02:01");
    dayNight("23:02:01");

}