#include <bits/stdc++.h>
using namespace std;

//--------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define LL long long
#define INF INT_MAX/3

//--------------------------------------------
const double EPS = 1e-14;
const double PI  = acos(-1.0);

//--------------------------------------------

int main(){
  int h,m;
  scanf("%d:%d",&h,&m);
  if ((m - 55) >= 0) h = (h + 1) % 24;
  m = (m + 5) % 60;
  printf("%02d:%02d\n",h,m);
}