#include "bits/stdc++.h"
using namespace std;
#ifdef _DEBUG
#include "dump.hpp"
#else
#define dump(...)
#endif

//#define int long long
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(c) begin(c),end(c)
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9) + 7;
const double PI = acos(-1);
const double EPS = 1e-9;
template<class T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	char s1, s2;
	int x, y;
	cin >> x >> s1 >> y;
	int time = x * 60 + y + 5;
	string a1, a2;
	if (time / 60 < 10)a1 += "0";
	a1 += to_string(time / 60);
	if (a1 == "24")a1 = "00";
	time %= 60;
	if (time < 10)a2 += "0";
	a2 += to_string(time);
	cout << a1 << ":" << a2 << endl;
	return 0;
}