/* -*- coding: utf-8 -*-
 *
 * 525.cc: No.525 二度寝の季節 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int hh, mm;
  scanf("%d:%d", &hh, &mm);

  int m = (hh * 60 + mm + 5) % (24 * 60);
  printf("%02d:%02d\n", m / 60, m % 60);

  return 0;
}