#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int A, B;
	string S;
	cin >> A >> B >> S;
	double utc = stod(S.substr(3));
	utc -= 9;
	utc *= 60;
	
	int t = A * 60 + B + (int)round(utc);
	t = (t + 60 * 24) % (60 * 24);
	printf("%02d:%02d\n", t / 60, t % 60);
}