#include <bits/stdc++.h>
using namespace std;
char ch[8];
int main() {
  int h, m, k;
  cin >> ch;
  h = (ch[0] - '0') * 10 + (ch[1] - '0');
  m = (ch[3] - '0') * 10 + (ch[4] - '0');
  cin >> k;
  m += k;
  h += (m / 60);
  m %= 60;
  h %= 24;
  if (h < 10) {
    cout << "0" << h << ":";
    if (m < 10)
      cout << "0" << m;
    else
      cout << m;
  } else {
    cout << h << ":";
    if (m < 10)
      cout << "0" << m;
    else
      cout << m;
  }
  return 0;
}
