#include<bits/stdc++.h>
using namespace std;
vector<int> cost;int N;
struct node {
vector<long long> dp;
long long free;
vector<node*> l;
int a;
};
void dfs(node* n, node* p){
for(node* c : n->l) if(c!=p) dfs(c,n);
n->dp.resize(N+1);
n->free = LONG_LONG_MAX;
for(int k = n->a+1;k <= N;k++){
n->dp[k] = cost[k];
for(node* c : n->l){
if(c==p) continue;
if(!c->a){
if(k == n->a+1) n->dp[k] += min(c->dp[k]-cost[k], c->free);
else n->dp[k] += c->free;
} else if(c->a == n->a+1){
if(k>c->a) n->dp[k] += min(c->dp[k]-cost[k], c->free);
else n->dp[k] += c->free;
} else n->dp[k] += c->free;
}
n->free = min(n->free, n->dp[k]);
}
}
void solve(){
int n;cin >> n;
N=n;
node g[n+1];
cost.resize(n+1);
for(int i = 1;i <= n;i++) cin >> g[i].a;
for(int i = 1;i <= n;i++) cin >> cost[i];
for(int i = 0;i < n-1;i++){
int u,v;cin >> u >> v;
g[u].l.push_back(&g[v]);
g[v].l.push_back(&g[u]);
}
dfs(&g[1], NULL);
cout << g[1].free << '\n';
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
}
