#include <bits/stdc++.h>

#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define RFOR(i, a, b) for (ll i = (b)-1; i >= (a); i--)
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define rep1(i, n) for (ll i = 1; i <= (n); i++)
#define rrep(i, n) for (ll i = (n)-1; i >= 0; i--)

#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define pii pair<int, int>
#define vi vector<int>

using namespace std;
template <class S, class T>
ostream& operator<<(ostream& o, const pair<S, T>& p)
{
    return o << "(" << p.first << "," << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& vc)
{
    o << "sz = " << vc.size() << endl
      << "[";
    for (const T& v : vc)
        o << v << ",";
    o << "]";
    return o;
}
using ll = long long;
constexpr ll MOD = 1000000007;

int main()
{
    char h[2];
    char cron;
    char m[2];
    cin >> h[0] >> h[1];
    cin >> cron;
    cin >> m[0] >> m[1];
    int hour = (h[0] - '0') * 10 + (h[1] - '0');
    int minute = (m[0] - '0') * 10 + (m[1] - '0');
    int tim = hour * 60 + minute + 5;
    if (tim >= 1440) {
        tim -= 1440;
    }
    hour = tim / 60;
    minute = tim % 60;
    if (hour < 10) {
        cout << 0;
    }
    cout << hour << ":";
    if (minute < 10) {
        cout << 0;
    }
    cout << minute << endl;
    return 0;
}