#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
#include <cmath>
using namespace std;
#define fastInp cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
typedef long long ll;
typedef long double ld;
const ll SZ = 200'100, LG = 18;
ll n;
vector<ll> vec;
vector<vector<ll>> gr;
ll up[SZ][LG], tin[SZ], tout[SZ], t = 0;
ll seg[SZ * 8], val[SZ], dp[SZ];
void upd(int v, int l, int r, int pos, int val) {
if (l == r - 1) {
seg[v] = val;
} else {
int mid = (l + r) / 2;
if (pos < mid) {
upd(v * 2 + 1, l, mid, pos, val);
} else {
upd(v * 2 + 2, mid, r, pos, val);
}
seg[v] = seg[v * 2 + 1] + seg[v * 2 + 2];
}
}
ll ask(int v, int l, int r, int askl, int askr) {
if (l >= askr || r <= askl) return 0;
if (askl <= l && r <= askr) return seg[v];
int mid = (l + r) / 2;
return ask(v * 2 + 1, l, mid, askl, askr) + ask(v * 2 + 2, mid, r, askl, askr);
}
void dfs(int v, int par = -1) {
for (int i = 1; i < LG; i++) {
up[v][i] = up[up[v][i - 1]][i - 1];
}
t++;
tin[v] = t;
for (auto to : gr[v]) {
if (to != par) {
dp[to] = dp[v] + 1;
up[to][0] = v;
dfs(to, v);
}
}
t++;
tout[v] = t;
}
bool is_par(int v, int u) {
return tin[v] <= tin[u] && tout[u] <= tout[v];
}
ll lca(int v, int u) {
if (is_par(v, u)) return v;
if (is_par(u, v)) return u;
for (int i = LG - 1; i >= 0; i--) {
if (!is_par(up[u][i], v)) u = up[u][i];
}
return up[u][0];
}
ll dist(int v, int u) {
ll lc = lca(u, v);
return dp[u] + dp[v] - 2 * dp[lc];
}
ll sum(int v, int u) {
ll lc = lca(u, v);
return ask(0, 0, SZ * 2, 0, tin[u] + 1) + ask(0, 0, SZ * 2, 0, tin[v] + 1) - 2 * ask(0, 0, SZ * 2, 0, tin[lc] + 1) + val[lc];
}
void toggle(int v) {
val[v] = 1;
upd(0, 0, 2 * SZ, tin[v], 1);
upd(0, 0, 2 * SZ, tout[v], -1);
}
ll dsu[SZ], opt[SZ];
ll find(int v) {
if (dsu[v] == v) return v;
return dsu[v] = find(dsu[v]);
}
void uni(int v, int u) {
v = find(v);
u = find(u);
if (v != u) {
dsu[u] = v;
}
}
int main() {
fastInp;
cin >> n;
vec.resize(n);
for (auto &c : vec) cin >> c;
vector<pair<ll, ll>> srt;
for (int i = 0; i < n; i++) {
srt.push_back({vec[i], i});
dsu[i] = i;
}
sort(srt.rbegin(), srt.rend());
gr.resize(n);
for (int i = 0; i < n - 1; i++) {
ll u, v;
cin >> u >> v;
u--; v--;
gr[u].push_back(v);
gr[v].push_back(u);
}
dfs(0);
ll prev = srt[0].second, ans = 0;
for (int ii = n - 1; ii >= 0; ii--) {
int i = srt[ii].second;
for (auto to : gr[i]) {
if (vec[to] < vec[i]) {
opt[i] = max(opt[i], opt[find(to)] + dist(find(to), i));
uni(i, to);
}
}
}
ans = opt[srt[0].second];
//for (auto c : srt) cout << c.first << " " << c.second << "\n";
cout << ans;
return 0;
toggle(prev);
srt.erase(srt.begin());
for (auto c : srt) {
int ind = c.second;
cerr << prev << " " << ind << " " << sum(prev, ind) << " " << dist(prev, ind) << "\n";
if (sum(prev, ind) == 1) {
ans += dist(prev, ind);
toggle(ind);
prev = ind;
}
}
cout << ans;
return 0;
}
