#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;


int main(void) {

  string s;
  cin >> s;
  int t = (s[0]-'0') * 10 + (s[1]-'0');
  t *= 60;
  t += (s[3]-'0') * 10 + (s[4]-'0') + 5;

  string ah = to_string((t / 60)%24);
  string am = to_string(t % 60);
  if( ah.size() == 1 ) ah = '0' + ah;
  if( am.size() == 1 ) am = '0' + am;
  cout << ah + ":" + am << endl;

  return 0;
}






// EOF