#include <bits/stdc++.h>
using namespace std;
int main() {
  string a, b;
  int m, h, add;
  cin >> a;
  h = atoi(a.substr(0, 2).c_str());
  m = atoi(a.substr(3, 2).c_str());
  cin >> add;
  m = m + add;
  if (m >= 60) {
    h = h + m / 60;
    m = m % 60;
    if (h >= 24) h = h % 24;
  }
  if (h < 10)
    cout << "0" << h << ":";
  else
    cout << h << ":";
  if (m < 10)
    cout << "0" << m;
  else
    cout << m;
  return 0;
}
