#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, m;
  char lixo;
  cin >> h >> lixo >> m;
  int a;
  cin >> a;
  m += a;
  h += m / 60;
  m %= 60;
  h %= 24;
  printf("%02d:%02d\n", h, m);
  return 0;
}
