#include <bits/stdc++.h>
using namespace std;
void solve() {
  int x, y, z, x1, y1;
  char k;
  cin >> x >> k >> y >> z;
  y1 = z + y;
  y = y1 % 60;
  x1 = y1 / 60;
  x = x + x1;
  x = x % 24;
  cout << x / 10 << x % 10 << ":" << y / 10 << y % 10 << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  { solve(); }
  return 0;
}
