#pragma GCC optimize ("Ofast")
#pragma GCC target ("avx2")
#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
using namespace std;
const int mxN = 3e5 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
const int block_sz = 500;
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
if (a < b) {a = b; return true;} return false;
}
struct DSU{
int n;
vector<int> lab;
vector<int> mx;
DSU(){}
DSU(int _n)
{
n = _n;
lab.resize(n + 7, -1);
mx.resize(n + 7);
}
int root(int u) {return lab[u] < 0 ? u : lab[u] = root(lab[u]);}
bool union_root(int u, int v)
{
u = root(u);
v = root(v);
if(u == v) return false;
if(lab[u] > lab[v]) swap(u, v);
lab[u] += lab[v];
lab[v] = u;
maximize(mx[u], mx[v]);
return true;
}
} dsu;
int n;
bool used[mxN];
pair<int, int> ed[mxN];
vector<int> adj[mxN];
int idx[mxN];
int best[mxN];
bool cmp(int a, int b)
{
return dsu.mx[a] < dsu.mx[b];
}
void solve()
{
cin >> n;
dsu = DSU(n);
for(int i = 1; i <= n; i++) cin >> dsu.mx[i];
for(int i = 1; i <= n; i++) idx[i] = i;
sort(idx + 1, idx + 1 + n, cmp);
for(int i = 1; i <= n; i++) best[idx[i]] = i;
for(int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
if(best[u] < best[v]) swap(u, v);
adj[u].pb(v);
}
ll res = 0;
for(int i = 1; i <= n; i++) {
int u = idx[i];
for(int v : adj[u]) {
res += dsu.mx[dsu.root(u)];
res += dsu.mx[dsu.root(v)];
dsu.union_root(u, v);
}
}
cout << res;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("task.inp", "r", stdin);
//freopen("task.out", "w", stdout);
int tc = 1;
//cin >> tc;
while(tc--) {
solve();
}
return 0;
}
