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

int main(){
    int h1,h2,m1,m2, tt;
    string T;
    cin >> T;

    h1 = T[0]-'0';
    h2 = T[1]-'0';
    m1 = T[3]-'0';
    m2 = T[4]-'0';

    tt = (h1*600+h2*60+m1*10+m2+5)%(24*60);

    cout << tt/600 << (tt%600)/60 << ':' << (tt%600%60)/10 << tt%10 << endl;

    return 0;
}