#include <bits/stdc++.h>

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int a,b;
    string s;
    
    cin >> a >> b >> s;

    string t = s.substr(4);

    int h,m;
    bool flag = false;
    
    for (int i = 0;i < t.size();i++){
        if (i == 0) h = t[i] - '0';
        else if (t[i] == '.') flag = true;
        else if (flag) m = (t[i] - '0') * 6;
        else {h *= 10;h += t[i] - '0';}
    }

    if (s[3] == '-') {h *= -1; m *= -1;}

    a += h - 9;
    b += m;

    if (b >= 60) {
        a += b/60;
        b %= 60;
    }
    if (b < 0) {
        a += b/60 - 1;
        b += 60*(-b/60 + 1);
    }
    if (a >= 24) {
        a = a-24;
    }
    if (a < 0) a += 24;

    if (a < 10) cout << '0' << a << ':' ;
    else cout << a << ':' ;
    if (b < 10) cout << '0' << b << endl;
    else cout << b << endl;

    return 0;

}