#include <bits/stdc++.h>

#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define endl "\n"
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rrep(i, n) for(int i = ((int)(n)-1); i >= 0; i--)
#define all(x) (x).begin(),(x).end()

using namespace std;
using ll = long long;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> P;
 
const int INF = 1e9;
//const ll INF = 1e18;
const double EPS = 1e-10;
const int MOD = 1e9+7;
const double PI = acos(-1.0);

int main()
{
	string s;
	cin >> s;
	int h = (s[0]-'0')*10+s[1]-'0';
	int m = (s[3]-'0')*10+s[4]-'0';
	m += 5;
	if(m >= 60){
		m %= 60;
		h++;
		if(h == 24) h = 0;
	}
	printf("%02d:%02d\n",h,m);
	return 0;
}