#include <bits/stdc++.h>
#define FOR(i, beg, ed, etr) for(ll i = beg;i <= ed;i += etr)
#define FORN(i, beg, ed, etr) for(ll i = beg;i >= ed;i -= etr)
#define all(x) x.begin(), x.end()
#define F first
#define pb push_back
#define con continue
#define S second
using namespace std;
typedef long long ll;
typedef double db;
typedef long double ld;
typedef pair<int,int> pii;
const ll inf = 1e9;
const ll INF = 1e13;
const ll N = 5e3 + 5;
const ll maxn = 5e6;
const ll MOD = 998244353;
ll a[N];
ll f[N];
vector <int> g[N];
ll dep[N],id[N];
ll dp[N],suf[N];
void dfs(int v,int p = 0){
id[dep[v]] = a[v];
for(int to : g[v]){
if(to != p){
dep[to] = dep[v] + 1;
dfs(to,v);
}
}
}
ll ql[N],qr[N];
void solve(){
int n;cin >> n;
FOR(i, 1, n, 1){
cin >> a[i];
dp[i] = INF;
}
FOR(i, 1, n, 1){
cin >> f[i];
}
suf[n] = f[n];
FORN(i, n-1, 1, 1){
suf[i] = min(suf[i+1],f[i]);
}
FOR(i, 2, n, 1){
ll u,v;cin >> u >> v;
g[u].pb(v);
g[v].pb(u);
}
dep[1] = 1;
dfs(1);
dp[1] = suf[id[1] + 1];
FOR(i, 2, n, 1){
ql[i] = i;
dp[i] = dp[i-1] + suf[id[i]+1];
while(ql[i] > 1){
if(a[ql[i] - 1] + 1 == a[ql[i]]){
ql[i] = ql[ql[i] - 1];
}
}
dp[i] = min(dp[i],dp[ql[i]-1] + suf[id[i]+1]);
qr[i] = ql[i];
if(qr[i] > 1){
if(id[qr[i] - 1] + 1 > id[i]){
int moad = a[qr[i] - 1] + 1;
qr[i] = qr[qr[i] - 1];
dp[i] = min(dp[i],dp[qr[i] - 1] + f[moad]);
}
}
}
cout << dp[n];
}
main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll abd = 1;
// cin >> abd;
FOR(i, 1, abd, 1){
solve();
}
}
