#include<bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3f
#define EPS (1e-10)
using namespace std;
typedef long long ll;
typedef pair<int, int>P;

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