#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  string S;
  cin>>S;
  int now = ((S[0]-'0')*10+(S[1]-'0'))*60+((S[3]-'0')*10+(S[4]-'0'));
  now += 5;
  now %= 1440;
  int a = now/60;
  int b = now%60;
  if(a < 10) cout<<'0'<<a<<':';
  else cout<<a<<':';
  if(b < 10) cout<<'0'<<b<<endl;
  else cout<<b<<endl;
}