#include <bits/stdc++.h>   using namespace std;   int main() {     int h, m;     char c;     cin >> h >> c >> m;     while (1 > 0) {       m++;       h += (m / 60);       m %= 60;       h %= 24;       if (h / 10 == m % 10 && h % 10 == m / 10) break;     }     cout << h / 10 << h % 10 <<  :  << m / 10 << m % 10;     return 0;   }   