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

int main(){
  int a,b;
  scanf("%d:%d",&a,&b);
  if(b+5>=60){
    if(a==23)cout << "00:";
    else{
      cout.width(2);
      cout.fill('0');
      cout << a+1 << ":";
    }
    cout << '0' << b-55 << endl;
  }else{
    cout.width(2);
    cout.fill('0');
    cout << a << ":";
    cout.width(2);
    cout.fill('0');
    cout << b+5 << endl;
  }
  return 0;
}