#include<iostream>
#include<string>
#include<cstring>
#include<complex>
#include<vector>
#include<algorithm>
#include<sstream>
#include<iomanip>
using namespace std;

#define REP(i, j) for (int i = 0; i < (int)j; ++i)
#define FOR(i, j, k) for (int i = (int)j; i < (int)k; ++i)
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
typedef complex<double> P;
typedef vector<int> VI;
typedef long long LL;
typedef pair<int,int> PII;

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

	string t;
	cin >> t;
	vector<string> v;
	stringstream ss(t);
	string buffer;
	while (getline(ss, buffer, ':')) {
		v.push_back(buffer);
	}
	int h = stoi(v[0]), m = stoi(v[1]);
	
	m += 5;
	if (m > 60) {
		m %= 60;
		if ((h+1) == 24) h = 0;
	}

	cout << setfill('0') << right << setw(2) << h;
	cout << ':';
	cout << setfill('0') << right << setw(2) << m << endl;

	return 0;
}