#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int h, m;
	char c;
	cin >> h >> c >> m;
	int sum = h * 60 + m;
	sum = (sum + 5) % (24 * 60);

	h = sum / 60, m = sum % 60;
	cout << h / 10 << h % 10 << ":" << m / 10 << m % 10 << endl;
}