#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define fi first
#define se second
int main(){
    string s;
    cin >> s;
    int h = stoi(s.substr(0, 2)), m = stoi(s.substr(3));
    m = (h * 60 + m + 5) % 1440;
    printf("%02d:%02d\n", m / 60, m % 60);
    return 0;
}