#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) for(int i = (n) - 1; (i) >= 0; --i)
#define SZ(n) (int)(n).size()
#define ALL(n) (n).begin(), (n).end()
#define MOD LL(1e9 + 7)
#define INF 1000000
using namespace std;
typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PI;

int main() {
	int a, b;
	string s;
	cin >> a >> b >> s;
	double t = stoi(s.substr(3, s.length() - 3));
	t *= 60;
	if (s[s.size() - 2] == '.')
		if (t > 0)
			t += (s[s.length() - 1] - '0') * 6;
		else
			t -= (s[s.length() - 1] - '0') * 6;
	b += t - 9 * 60 + a * 60 + 1440;
	b %= 1440;
	a = b / 60;
	b = b % 60;
	string h = to_string(a);
	string m = to_string(b);
	if (h.length() == 1)
		h.insert(0, "0");
	if (m.length() == 1)
		m.insert(0, "0");
	cout << h << ":" << m << endl;
	return 0;
}