#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<ll> A(N);
    for (auto &x : A) cin >> x;

    vector<vector<int>> G(N);
    for (int i = 0; i < N - 1; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        G[u].push_back(v);
        G[v].push_back(u);
    }

    vector<ll> ans(N, -(1LL << 60));

    for (int s = 0; s < N; ++s) {
        vector<int> par(N, -1), dep(N), order = {s};
        vector<ll> sum(N), best(N);
        sum[s] = A[s];

        for (int i = 0; i < (int)order.size(); ++i) {
            int v = order[i];
            for (int u : G[v]) {
                if (u == par[v]) continue;
                par[u] = v;
                dep[u] = dep[v] + 1;
                sum[u] = sum[v] + A[u];
                order.push_back(u);
            }
        }

        for (int v : order)
            best[v] = sum[v] - dep[v];

        for (int i = N - 1; i > 0; --i) {
            int v = order[i];
            best[par[v]] = max(best[par[v]], best[v]);
        }

        for (int v = 0; v < N; ++v)
            ans[v] = max(ans[v], best[v]);
    }

    cout << *min_element(ans.begin(), ans.end()) << '\n';
}