#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

int main() {
  string T; cin >> T;
  int time = stoi(T.substr(0,2))*60 + stoi(T.substr(3,5)) + 5;
  time %= 1440;
  printf("%02d:%02d\n", time/60, time%60);
}