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

void solve() {
  int hh, mm, t;
  string s;
  scanf("%d:%d", &hh, &mm);
  t = (hh * 60 + mm + 5) % 1440;
  hh = t / 60;
  mm = t % 60;
  printf("%02d:%02d", hh, mm);
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
}