#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <string>
typedef long long ll;
using namespace std;

double strNum(string s) {
    double n = 0;
    int dec = 0;
    for (int i = 0; i < (int)s.length(); i++) {
        if (s[i] == '.') {
            dec = true;
        }
        else if (dec){
            double d = 1;
            for(int i = 0; i < dec; i++)
            {
                d *= 0.1;
            }
            n += (s[i] - '0') * d;
            dec++;
        }
        else if (s[i] - '0' >= 0 && s[i] - '0' <= 9){
            n *= 10;
            n += (s[i] - '0');
        }
    }
    if (s[0] == '-') {
        n *= -1;
    }
    return n;
}

int main(){
    int a,b,t;
    string s;
    cin >> a >> b >> s;
    t = 24 * 60 + (int)(a * 60 + b - (9 - strNum(s.substr(3,s.length()-3))) * 60);
    t %= 24 * 60;
    cout << t/60%24/10 << t/60%24%10 << ":" << t%60/10 << t%60%10 << endl;
    return 0;
}