#define _USE_MATH_DEFINES

#include <iostream>	//cin, cout
#include <vector>	//vector
#include <algorithm> //sort,min,max,count
#include <string>	//string,getline
#include <ios>		//fixed
#include <iomanip>	//setprecision
#include <utility> //swap
#include <cstdlib>	//abs(int)
#include <cmath>	//sqrt
#include <sstream>	//stringstream,getline
#include <cmath>	//ceil,M_PI
#include <numeric>	//gcd

using namespace std;

int main() {

	string S;
	cin >> S;

	int h = stoi(S.substr(0, 2));
	int m = stoi(S.substr(3, 2));

	m = m + 5;
	if (m >= 60) {
		m = m % 60;
		h++;
	}

	if (h >= 24) {
		h = h % 24;
	}

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

	return 0;

}