#include<iostream>
using namespace std;

int main(){
    double a, b;
    string t;
    cin >> a >> b >> t;
    double utc = (stod(t.substr(3, t.size()))) - 9.0;
    double difmin = (utc*10*6);
    b += difmin;
    if(b >= 60){
        a += (int)b/60;
        b -= (int)b/60 * 60;
    }else if(b < 0){
        while(b < 0){
            a--;
            b += 60.0;
        }
    }

    if(a < 0)   a += 24;
    if(a > 24)  a -= 24;

    cout << (10 > a ? "0" : "") << a << ":" << (10 > b ? "0" : "") << b << endl;
    return 0;
}