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

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