#include <bits/stdc++.h>
using namespace std;

int main() {
  int a, b;
  string S;
  cin >> a >> b >> S;
  double D = stod(S.substr(3));
  D += (D >= 0) ? 1e-10 : -1e-10;
  struct tm t = {};
  t.tm_hour = a - 9;
  t.tm_min = b + D * 60;
  mktime(&t);
  printf("%02d:%02d", t.tm_hour, t.tm_min);
}