#include <bits/stdc++.h>
using namespace std;
int N;
int lst[100100];
int invlst[100100];
int cont = 0;
int pre[100100];
int post[100100];
vector<int> adjlst[100100];
int parent[100100];
bool done[100100];
int u,v;
struct node{
int s, e, m;
node *l, *r;
pair<int,int> v;
node(int S, int E){
s = S;
e = E;
m = (s + e)/2;
if(s != e){
l = new node(s,m);
r = new node(m + 1, e);
v = max(l -> v, r -> v);
}
else v = {lst[invlst[s]],invlst[s]};
}
pair<int,int> query(int S,int E){
if(S <= s && e <= E) return v;
pair<int,int> V = {-1,-1};
if(S <= m) V = max(l -> query(S,E),V);
if(m < E) V = max(r -> query(S,E),V);
return V;
}
void update(int i){
if(s == e){
v = {-1,-1};
return;
}
if(i <= m) l -> update(i);
else r -> update(i);
v = max(l -> v, r -> v);
}
}*root;
void dfs(int i, int p){
parent[i] = p;
pre[i] = cont;
cont++;
for(int j : adjlst[i]){
if(j == p) continue;
dfs(j,i);
}
post[i] = cont - 1;
}
long long int solve(int i, int l, int r){
long long int ans = 0;
for(int j : adjlst[i]){
if(j == parent[i]) continue;
if(done[j]) continue;
ans += (root -> query(pre[j],post[j])).first + lst[i];
}
root -> update(pre[i]);
if(parent[i] != -1 && !done[parent[i]]){
ans += (root -> query(l,r)).first + lst[i];
}
done[i] = true;
for(int j : adjlst[i]){
if(j == parent[i]) continue;
if(done[j]) continue;
int k = (root -> query(pre[j],post[j])).second;
ans += solve(k,pre[j],post[j]);
}
if(parent[i] != -1 && !done[parent[i]]){
int k = (root -> query(l,r)).second;
ans += solve(k,l,r);
}
return ans;
}
int main(){
scanf(" %d",&N);
for(int i = 1; i <= N; i++){
scanf(" %d",&lst[i]);
done[i] = false;
}
for(int i = 0; i < N - 1; i++){
scanf(" %d",&u);
scanf(" %d",&v);
adjlst[u].push_back(v);
adjlst[v].push_back(u);
}
dfs(1,-1);
for(int i = 1; i <= N; i++){
invlst[pre[i]] = i;
}
root = new node(0,N-1);
printf("%lld",solve( (root -> query(0,N-1) ).second , 0, N - 1) );
}
