#include <bits/stdc++.h>

int main() {
  std::string s;
  std::cin >> s;
  int a[2]{};
  a[0] = std::stoi(std::string{s.begin(), s.begin()+2});
  a[1] = std::stoi(std::string{s.begin()+3, s.begin()+5});
  int b = a[0] * 60 + a[1] + 5;
  printf("%02d:%02d\n", b/60%24, (b-a[0]*60)%60);
}