#include <bits/stdc++.h>
//#define DEBUG 1106
#define int long long
#define ll long long
#define ld long double
#define pb emplace_back
#define p_q priority_queue
#define m_p make_pair
#define pii pair<int,int>
#define endl '\n'
#define INIT ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define forn(i,n) for (int i = 0; i < n; i++)
#define forn1(i,n) for (int i = 1; i <= n; i++)
#define all(x) x.begin(),x.end()
#define ft first
#define sd second
#define lowbit(x) (x&(-x))
#define chmax(x,y) x=max(x,y)
#define chmin(x,y) x=min(x,y)
#ifdef DEBUG
#define debug(x) cout << #x << ": " << x << endl;
#else
#define debug(x) 1106;
#endif
using namespace std;
const int N = 1e6+5;
const int M = 2005;
const int inf = 1e9;
const int INF = 1e18;
const int MOD = 1e9+7;
pii e[N];
int a[N], p[N], sz[N];
int getp(int x) {
if(x!=p[x]) p[x] = getp(p[x]);
return p[x];
}
int m(int x, int y) {
x = getp(x), y = getp(y);
p[y] = x;
int ans = sz[x]+sz[y];
sz[x] = max(sz[x],sz[y]);
sz[y] = max(sz[x],sz[y]);
return ans;
}
bool cmp(pii x, pii y) {
return max(a[x.ft],a[x.sd])<max(a[y.ft],a[y.sd]);
}
signed main() {
INIT
#ifdef DEBUG
freopen("input.txt", "r", stdin);
#endif
///////////
int n;
cin >> n;
forn1(i,n) cin >> a[i];
forn1(i,n) p[i]=i, sz[i]=a[i];
forn(i,n-1) {
cin >> e[i].ft >> e[i].sd;
}
sort(e,e+n-1,cmp);
int c = 0;
forn(i,n-1) {
c += m(e[i].ft,e[i].sd);
}
cout << c;
}
