#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, m, ti;
  scanf("%d:%d", &h, &m);
  scanf("%d", &ti);
  int realh = ti / 60, realmin = ti % 60;
  while (realh--) {
    if (h == 23)
      h = 0;
    else
      h++;
  }
  while (realmin--) {
    if (m == 59) {
      m = 0;
      if (h == 23)
        h = 0;
      else
        h++;
    } else
      m++;
  }
  if (h < 10) printf("0");
  printf("%d:", h);
  if (m < 10) printf("0");
  printf("%d", m);
  return 0;
}
