#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "math.h"
#include "utility"
#include "string"
#include "map"
#include "unordered_map"
#include "iomanip"
#include "random"

using namespace std;
const long long int MOD = 1000000007;
list<long long int> Prime(int M) {
	list<long long int>P;
	P.push_back(2);
	P.push_back(3);
	for (int i = 5; i <= M; i += 6) {
		bool flag = true;
		for (auto j : P) {
			if (i%j == 0) {
				flag = false;
				break;
			}
		}
		if (flag)P.push_back(i);
		flag = true;
		for (auto j : P) {
			if ((i + 2) % j == 0) {
				flag = false;
				break;
			}
		}
		if (flag)P.push_back(i + 2);
	}
	return P;
}

long long int N, K, Q, M;

string s;

int main() {
	ios::sync_with_stdio(false);
	cin >> s;
	s[4] += 5;
	if (s[4]  > '9') {
		s[4] -= 10;
		s[3]++;
	}
	if (s[3] > '5') {
		s[3] -= 6;
		s[1]++;
	}
	if ((s[0]-'0')*10+s[1]-'0' ==24 ) {
		s[1] = '0';
		s[0] = '0';
	}
	if ((s[0] - '0') * 10 + s[1] - '0' == 10) {
		s[0] = '1';
		s[1] = '0';
	}
	if ((s[0] - '0') * 10 + s[1] - '0' == 20) {
		s[0] = '2';
		s[1] = '0';
	}
	cout << s << endl;
	return 0;
}