#include <iostream>
#include <string>
using namespace std;

int main(){
    string t; cin >> t;
    string temp;
    string h;
    string m;

    //まずは：を除いたstring型を成形
    temp = t[0];
    h = temp;
    temp = t[1];
    h += temp;

    temp = t[3];
    m = temp;
    temp = t[4];
    m += temp;

    //整数に変換
    int min, hour;
    min = stoi(m);
    hour = stoi(h);

    min += 5;
    if(min >= 60){
        min = min-60;
        hour += 1;
        if(hour >= 24){
            hour = 0;
        }
    }

    if(min < 10 && hour < 10) cout << "0" << hour << ":" << "0" << min << endl;
    else if(min < 10) cout << hour << "0" << ":" << min << endl;
    else if(hour < 10) cout << "0" << hour << ":" << min << endl;
    else cout << hour << ":" << min << endl;

    return 0;
}