#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll a, b;
    string s;
    cin >> a >> b >> s;
    double time = a * 60 + b;
    double d = 0;
    double k = 1;
    rrep(i, len(s)) {
        if (s[i] == '+') break;
        if (s[i] == '-') {
            d *= -1;
            break;
        }
        if (s[i] == '.') {
            ll x = len(s) - i - 1;
            ll div = 1;
            rep(j, x) div *= 10;
            k = 0.1;
            d /= div;
        }
        else {
            d += k * (s[i] - '0');
        }
        k *= 10;
    }
    ll nt = (d - 9) * 60;
    ll ans = ((ll)time + 24 * 60 + nt) % (24 * 60);
    printf("%02lld:%02lld\n", ans / 60, ans % 60);
    return 0;
}