#include <bits/stdc++.h>
using namespace std;
int main() {
  string tm;
  cin >> tm;
  int a;
  cin >> a;
  int hr = (tm[0] - '0') * 10 + tm[1] - '0';
  int min = (tm[3] - '0') * 10 + tm[4] - '0';
  int full = hr * 60 + min + a;
  int hh = (full / 60) % 24;
  int mm = full % 60;
  if (hh < 10)
    cout << 0 << hh;
  else
    cout << hh;
  cout << ":";
  if (mm < 10)
    cout << 0 << mm;
  else
    cout << mm;
  return 0;
}
