#include <bits/stdc++.h>
//#include <ext/pb_ds/detail/standard_policies.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define F first
#define S second
#define ll long long
#define ld long double
#define endl '\n'
#define TIME 1.0*clock()/CLOCKS_PER_SEC
#define null NULL

using namespace std;

//using namespace __gnu_pbds;
//typedef tree <pii,null_type,less<pii>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;

mt19937 gen(chrono::system_clock::now().time_since_epoch().count());

const int M = 1e9 + 7;
const int FFTM = 998244353;
const int N = 2e5 + 7;

struct segtree{
    int tn = 1;
    vector<int> t;

    segtree(){}

    segtree(int n){
        tn = 1;
        while (tn < n) tn <<= 1;
        t.resize(tn<<1|1, -1e9 - 7);
    }

    resize(int n){
        tn = 1;
        while (tn < n) tn <<= 1;
        t.assign(tn<<1|1, -1e9 - 7);
    }

    void clear(){
        t.assign(t.size(), -1e9 - 7);
    }

    void upd(int v, int tl, int tr, int p, int x){
        if (tr - tl == 1){
            t[v] = max(t[v], x);
            return;
        }
        int m = (tl + tr)>>1;
        if (p < m) upd(v<<1, tl, m, p, x);
        else upd(v<<1|1, m, tr, p, x);
        t[v] = max(t[v<<1], t[v<<1|1]);
    }

    void upd(int p, int x){
        upd(1, 0, tn, p, x);
    }

    int q(int v, int tl, int tr, int l, int r){
        if (tr <= l || r <= tl) return -1e9 - 7;
        if (l <= tl && tr <= r) return t[v];
        int m = (tl + tr)>>1;
        return max(q(v<<1, tl, m, l, r), q(v<<1|1, m, tr, l, r));
    }

    int q(int l, int r){
        return q(1, 0, tn, l, r);
    }
};

int n, sz[N], U[N], x[N], p, a, b, VV;
vector<int> now, g[N];
segtree t;
ll res = -1;

int Pos(int x){
    int p = upper_bound(now.begin(), now.end(), x) - now.begin();
    return p - 1;
}

void calc(int v, int p){
    sz[v] = 1;
    for (auto to : g[v])
        if (to != p && !U[to]) calc(to, v), sz[v] += sz[to];
}

int Find(int v, int p, int k){
    for (auto to : g[v])
        if (to != p && !U[to] && sz[to] >= k) return Find(to, v, k);
    return v;
}

void upd(int v, int p, int d = 1){
    t.upd(Pos(x[v]), d);
    for (auto to : g[v])
        if (to != p && !U[to]) upd(to, v, d + 1);
}

void solve(int v, int p, int d = 1){
    res = max(res, 1ll*(1ll*t.q(Pos(x[v]), now.size()) + d)*x[v]);
    for (auto to : g[v])
        if (to != p && !U[to]) solve(to, v, d + 1);
}

void P(int v, int p, vector<int> &A){
    A.pb(x[v]);
    for (auto to : g[v])
        if (to != p && !U[to]) P(to, v, A);
}

void go(int v){
    calc(v, v);
    int V = Find(v, v, sz[v]/2);VV = V;
    vector<int> all;
    P(V, V, all);
    sort(all.begin(), all.end());
    all.resize(distance(all.begin(), unique(all.begin(), all.end())));
    now = all;
    t.resize(all.size() + 1);
    for (int i = 0; i < g[V].size(); i++){
        int to = g[V][i];
        if (U[to]) continue;
        solve(to, V);
        upd(to, V);
    }
    t.clear();
    for (int i = g[V].size() - 1; i >= 0; i--){
        int to = g[V][i];
        if (U[to]) continue;
        solve(to, V);
        upd(to, V);
    }
    U[V] = 1;
    for (auto to : g[V])
        if (!U[to]) go(to);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    freopen("tree.in", "r", stdin);
    freopen("tree.out", "w", stdout);
#endif // LOCAL
    cin >> n;
    for (int i = 0; i < n; i++) cin >> x[i];
    for (int i = 1; i < n; i++) cin >> a >> b, a--, b--, g[a].pb(b), g[b].pb(a);
    go(0);
    cout << res;
    return 0;
}