#include <iostream>
#include <algorithm>
#include <string>
#include <sstream>
#include <iomanip>
#define rep(i, a, n) for(int i = a;i < n;i++)
#define repr(i, a, n) for(int i = a;i > n;i--)
using namespace std;


int a, b;
string s;
int t;
double utc;


void input(){
	cin >> a >> b >> s;
	string s1;
	rep(i, 3,(int)s.size()) s1.push_back(s[i]);
	stringstream ss;
	ss << s1;
	ss >> utc;
}


void solve(){
	t = a*60 + b;
	t += (int)((utc - 9.0)*60);
	int h = (int)(t/60 + 24) % 24;
	int m = t % 60;
	cout << setfill('0') << setw(2) << h << ':';
	cout << setfill('0') << setw(2) << m << endl;
}


int main(){
	input();

	solve();

	return 0;
}