#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long lint;

#define MIN(a,b) ((a)<(b)?(a):(b))
#define MAX(a,b) ((a)>(b)?(a):(b))

int main()
{
	int h, m, t;
	scanf("%d:%d", &h, &m);
	t = (h * 60 + m + 5) % 1440;
	printf("%02d:%02d\n", t / 60, t % 60);

	return 0;
}