#include <bits/stdc++.h>
using namespace std;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
const int man = (int)(1e5 + 500);
int n;
int sz[man], c[man], pr[man], x[man], y[man];
long long a[man], val[man];
bool was[man];
vector <array <int, 2> > g[man];
vector <array <int, 2> > ops;
int f(int x) {
return (x == pr[x]) ? x : pr[x] = f(pr[x]);
}
void un(int x, int y) {
x = f(x);
y = f(y);
if (sz[x] < sz[y]) {
swap(x, y);
}
val[x] = max(val[x], val[y]);
sz[x] += sz[y];
pr[y] = x;
}
bool cmp(int x, int y) {
return (a[x] > a[y]);
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 0; i < n; ++i) {
cin >> a[i];
c[i] = i;
pr[i] = i;
val[i] = a[i];
sz[i] = 1;
}
for (int i = 0; i < (n - 1); ++i) {
cin >> x[i] >> y[i];
--x[i], --y[i];
g[x[i]].push_back({y[i], i});
g[y[i]].push_back({x[i], i});
}
sort(c, c + n, cmp);
for (int i = 0; i < n; ++i) {
int v = c[i];
for (auto& u : g[v]) {
if (was[u[1]] == true) {
continue;
}
was[u[1]] = true;
ops.push_back({v, u[0]});
}
}
long long ans = 0;
reverse(ops.begin(), ops.end());
// cerr << (int)(ops.size()) << "\n";
for (auto& i : ops) {
ans += val[f(i[0])] + val[f(i[1])];
un(i[0], i[1]);
}
cout << ans << "\n";
return 0;
}
