#include <bits/stdc++.h>
using namespace std;
int main(int argc, char** argv) {
  char a[10];
  int n;
  cin >> a;
  char x[10], y[10];
  strcpy(y, &a[3]);
  strncpy(x, a, 2);
  int h, m;
  h = atoi(x);
  m = atoi(y);
  int n2, i = 0;
  cin >> n;
  n2 = m + n;
  while (n2 > 59) {
    n2 = n2 - 60;
    i++;
  }
  h = h + i;
  m = n2;
  while (h > 23) h = h - 24;
  printf("%02d%c%02d", h, ':', m);
  return 0;
}
