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

int main() {
    string s;
    cin >> s;
    int h = stoi(s.substr(0, 2));
    int m = stoi(s.substr(3, 2));
    
    if ((m += 5) >= 60) {
        m -= 60;
        h = (h + 1) % 24;
    }
    
    string ansh = to_string(h);
    if (ansh.size() == 1) ansh = "0" + ansh;
    string ansm = to_string(m);
    if (ansm.size() == 1) ansm = "0" + ansm;
    cout << ansh << ':' << ansm << '\n';
    return 0;
}