#include<bits/stdc++.h>
#define iter(a) a.begin(), a.end()
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mp make_pair
#define F first
#define S second
#define lsort(a) sort(iter(a))
#define eb emplace_back
#define gsort(a) sort(iter(a), greater<>());
using namespace std;
typedef long long ll;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<pll> a(n);
for(int i = 1; i <= n; i++) cin >> a[i-1].F, a[i-1].S = i;
gsort(a);
vector<vector<int>> g(n + 1);
vector<int> deg(n + 1);
for(int i = 1; i < n; i++){
int u, v;
cin >> u >> v;
g[u].eb(v);
g[v].eb(u);
deg[u]++; deg[v]++;
}
ll ans = 0;
for(int i = 0; i < n; i++){
ans += a[i].F * deg[a[i].S];
if(i) ans += a[i].F;
for(int j : g[a[i].S]) deg[j]--;
}
cout << ans << "\n";
return 0;
}
