#include "bits/stdc++.h"
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif
using ll = long long;
using pii = pair<int, int>;
#define F first
#define S second
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll get_rand(ll l, ll r) {
assert(l <= r);
return uniform_int_distribution<ll> (l, r)(rng);
}
const int N = 1e5 + 3;
struct Edge{
int u, v;
ll w;
bool operator < (const Edge &o) const {
return w < o.w;
}
};
struct DSU{
vector<ll> p, sz, mx;
int comp;
void init(int n){
p.resize(n + 2, 0);
sz.resize(n + 2, 0);
mx.resize(n + 2, 0);
comp = n;
for(int i = 1; i <= n; ++i)
p[i] = i, sz[i] = 1, mx[i] = 0;
}
int find_set(int u){
return u == p[u] ? u : p[u] = find_set(p[u]);
}
ll join_sets(int u, int v, ll x, ll y){
u = find_set(u), v = find_set(v);
mx[u] = max(mx[u], x);
mx[v] = max(mx[v], y);
if(u == v)
return 0;
--comp;
if(sz[u] < sz[v])
swap(u, v);
ll res = mx[u] + mx[v];
p[v] = u;
sz[u] += sz[v];
mx[u] = max(mx[u], mx[v]);
return res;
}
} dsu;
int n;
ll a[N];
vector<Edge> e;
void solve(){
cin >> n;
for(int i = 1; i <= n; ++i)
cin >> a[i];
for(int i = 1; i < n; ++i){
int u, v;
cin >> u >> v;
ll w = max(a[u], a[v]);
e.push_back({u, v, w});
}
sort(all(e));
dsu.init(n);
ll res = 0;
for(auto [u, v, w] : e)
res += dsu.join_sets(u, v, a[u], a[v]);
cout << res;
}
int32_t main() {
cin.tie(nullptr)->sync_with_stdio(0);
#define task "paradigm"
if(fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
int test = 1;
// cin >> test;
for(int i = 1; i <= test; ++i){
// cout << "Case #" << i << ": ";
solve();
}
#ifdef LOCAL
cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
#endif
return 0;
}
