//subtask3
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
vector <vector <int>> adj;
vector <int> vals;
struct DSU {
vector <int> link, sz, mx_val;
DSU (int s) {
link = sz = mx_val = vector <int> (s+1);
for (int i = 1; i <= s; i++) {
link[i] = i;
sz[i] = 1;
mx_val[i] = vals[i];
}
}
int head(int x) {
while (x != link[x])
x = link[x];
return x;
}
void unite(int a, int b) {
a = head(a);
b = head(b);
if (a == b)
return;
if (sz[a] < sz[b])
swap(a, b);
sz[a] += sz[b];
link[b] = a;
mx_val[a] = max(mx_val[a], mx_val[b]);
}
ll get_mx_val(int x) {
return mx_val[head(x)];
}
};
bool comp(int a, int b) {
return vals[a] < vals[b];
}
int main() {
int n;
cin >> n;
vals.resize(n+1);
adj.resize(n+1);
for (int i = 1; i <= n; i++)
cin >> vals[i];
for (int i = 0; i < n-1; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
DSU dsu(n+1);
vector <int> ord(n+1);
for (int i = 1; i <= n; i++)
ord[i] = i;
sort(ord.begin(), ord.end(), comp);
vector <bool> activated(n+1);
ll ans = 0;
for (int i = 1; i <= n; i++) {
int id = ord[i];
activated[id] = true;
ll added = 0;
for (auto j : adj[id]) {
if (activated[j]) {
added++;
ans += dsu.get_mx_val(j);
dsu.unite(j, id);
}
}
ans += added * vals[id];
}
cout << ans << '\n';
}
