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

// This function CHANGES the values of h, m, s that are passed to it.
// It moves the time forward by 'delta' seconds.
void travel(int &h, int &m, int &s, int delta) {
    const int SECONDS_PER_DAY = 24 * 60 * 60; // 86400

    // Convert current time to total seconds since midnight
    int total = h * 3600 + m * 60 + s;

    // Move forward by delta seconds
    total += delta;

    // Wrap around within a 24-hour day
    total %= SECONDS_PER_DAY;
    if (total < 0) {
        total += SECONDS_PER_DAY;
    }

    // Convert back to hours, minutes, seconds
    h = total / 3600;
    int leftover = total % 3600;
    m = leftover / 60;
    s = leftover % 60;
}

// Print time in 12-hour format with a.m./p.m.
void print_time_12h(int h, int m, int s) {
    bool pm = (h >= 12);
    int display_h = h % 12;
    if (display_h == 0) {
        display_h = 12;
    }

    cout << display_h << ':'
         << setw(2) << setfill('0') << m << ':'
         << setw(2) << setfill('0') << s << ' '
         << (pm ? "p.m." : "a.m.");
}

int main() {
    // Starting time: 6:00:00 p.m. = 18:00:00 in 24-hour time
    int hour   {18};
    int minute {0};
    int second {0};

    cout << "How many seconds forward do you want to go from 6:00:00 p.m.? ";

    int distance {};
    if (!(cin >> distance)) {
        cerr << "That wasn't a valid number of seconds.\n";
        return EXIT_FAILURE;
    }

    // This call will CHANGE hour, minute, second
    travel(hour, minute, second, distance);

    cout << "The new time is ";
    print_time_12h(hour, minute, second);
    cout << '\n';

    return EXIT_SUCCESS;
}