#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <cstdlib>
#include <cstdio>

using namespace std; 

int main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  int x = (a + 24) * 60 + b;

  x += (int)(atof(s.data() + 3) * 60) - 9 * 60;

  printf("%02d:%02d\n", x / 60 % 24, x % 60);
}