#include <bits/stdc++.h>
using namespace std;
long long i, j, n, h, m;
string s;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> s;
  cin >> n;
  h = (s[0] - 48) * 10 + s[1] - 48;
  m = (s[3] - 48) * 10 + s[4] - 48;
  m += n;
  h += m / 60;
  m %= 60;
  h %= 24;
  if (h < 10) cout << "0";
  cout << h << ":";
  if (m < 10) cout << "0";
  cout << m << '\n';
  return 0;
}
