struct dinic {
    // ...
};

void solve() {
    read(int, n, m, s, t);
    dinic net(n + 1);
    int S = 0, T = n + 1;
    vector<int> init(n + 1);
    for (int i = 0 ;i  < m; ++i) {
        read(int, u, v, lower, upper);
        init[v] += lower;
        init[u] -= lower;
        net.add_edge(u, v, upper - lower);
    }
    int sum = 0;
    for (int i  =1; i <= n; ++i) {
        if (init[i] > 0) {
            net.add_edge(S, i, init[i]);
            sum += init[i];
        } else if (init[i] < 0) {
            net.add_edge(i, T, -init[i]);
        }
    }
    net.add_edge(t, s, INF);  // WARN: s->t is wrong
    if (sum != net.run(S, T)) {
        cout << "please go home to sleep\n";
    } else {
        cout << net.run(s, t) << '\n';
    }
}