#include <iostream>
#include <string>

int main() {
  std::string T;
  std::cin >> T;
  int h, m;
  h = (T[0]-'0') * 10 + (T[1] - '0');
  m = (T[3]-'0') * 10 + (T[4] - '0');
  m += 5;
  if (m > 59) {
    ++h;
    m -= 60;
  }
  h %= 24;
  std::cout << h / 10 << h % 10 << ":" << m / 10 << m % 10 << std::endl;
  return 0;
}