#include <bits/stdc++.h>
using namespace std;
int main() {
  long long h, m, mm;
  char a;
  cin >> h >> a >> m;
  cin >> mm;
  m += mm;
  while (m >= 60) {
    m -= 60;
    h++;
  }
  while (h >= 24) {
    h -= 24;
  }
  if (h < 10) {
    cout << "0" << h << ":";
  } else {
    cout << h << ":";
  }
  if (m < 10) {
    cout << "0" << m << endl;
  } else {
    cout << m << endl;
  }
  return 0;
}
