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

string T;

int main() {
    cin >> T;

    int hour = stoi(T.substr(0, 2));
    int minute = stoi(T.substr(3, 2));

    minute += 5;
    if (minute >= 60) {
        ++hour;
        minute %= 60;

        if (hour > 23) hour %= 24;
    }

    cout << setw(2) << setfill('0') << hour << ":" << setw(2) << setfill('0') << minute << endl;
}