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

int main(){
    int h,m;
    char c;
    cin >> h>>c>>m;
    m+=5;
    if(m>59){
        m-=60;
        h+=1;
        if(h>23) h-=24;
    }
    cout<<(h<10?"0":"")<<h<<c<<(m<10?"0":"")<<m<<endl;
	return 0;
}