#include <bits/stdc++.h>
#define loop(i, a, b) for(long long i=a;i<b;i++)
#define pool(i, a, b) for(long long i=a-1;i>=b;i--)
#define fore(i, a) for(auto&& i:a)
#define fi first
#define se second
#define ps(a) push_back(a)
#define pb(a) pop_back(a)
#define sc scanf
#define vc vector
#define ll long long
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define llmax LLONG_MAX/2
#define llmin -LLONG_MAX/2
using namespace std;
#define mn 101000
#define par pair<ll, ll>
#define ld long double
#define mod 1000000007
ll arr[mn], dsu[mn], pos[mn], lar[mn], siz[mn];
par srt[mn];
vc<ll> edg[mn];
ll fnd(ll u){return (u==dsu[u]) ? u:fnd(dsu[u]);}
int main() {
ll n;cin >> n;
loop(i, 1, n+1) cin >> arr[i];
loop(i, 1, n+1) srt[i].fi=arr[i], srt[i].se=i, dsu[i]=i, siz[i]=1;
sort(srt+1, srt+n+1);
loop(i, 1, n+1) lar[srt[i].se]=i;
loop(i, 0, n-1){
ll a, b;cin >> a >> b;
edg[a].ps(b);
edg[b].ps(a);
}
ll ans=0;
loop(i, 1, n+1){
ll u=srt[i].se;
fore(v, edg[u]){
ll pv=fnd(v), pu=fnd(u);
if(lar[pv]<lar[pu]){
ans+=srt[lar[pu]].fi+srt[lar[pv]].fi;
if(siz[pv]>siz[pu]) swap(pv, pu);
dsu[pv]=pu;
lar[pu]=max(lar[pu], lar[pv]);
siz[pu]+=siz[pv];
}
}
}
cout << ans << endl;
}
