#include <bits/stdc++.h>
using namespace std;
int main() {
  char t[6], b = '0';
  int a, h, m;
  gets(t);
  cin >> a;
  h = (t[0] - 48) * 10 + t[1] - 48;
  m = (t[3] - 48) * 10 + t[4] - 48;
  m += a;
  h += m / 60;
  m %= 60;
  h %= 24;
  if (h / 10 == 0)
    cout << 0 << h;
  else
    cout << h;
  cout << ':';
  if (m / 10 == 0)
    cout << 0 << m;
  else
    cout << m;
  return 0;
}
