#include <bits/stdc++.h>
using namespace std;
char stack[10000001];
int main() {
  short a, b;
  char c;
  int d;
  cin >> a >> c >> b >> d;
  b += d;
  while (b >= 60) {
    a++;
    b -= 60;
  }
  while (a >= 24) {
    a -= 24;
  }
  printf("%02d:%02d", a, b);
}
