#include <iostream>

#include <vector>
#include <string>
#include <algorithm>
//---------------------------
using namespace std;
//---------------------------
#define REP(i,n) for(int i = 0; i < (n); i++)
#define P(x) cout << (x) << "\n"
//---------------------------


int main(){

  int h,m;
  scanf("%d:%d\n",&h,&m);
  int M = (m + 5) % 60;
  int H = (h + (m + 5) / 60) % 24;
  printf("%02d:%02d\n",H,M);

  return 0;
}