#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define F first
#define S second
#define sz(x) int(x.size())
const ll INF=1e18+5;
int n;
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
vector<int> a(n+1);
for(int i=1; i<=n; i++) {
cin >> a[i];
}
vector<ll> f(n+1);
for(int k=1; k<=n; k++) {
cin >> f[k];
}
for(int i=0; i<n-1; i++) {
int x, y;
cin >> x >> y;
}
vector<ll> suff(n+1);
suff[n]=f[n];
for(int i=n-1; i>=1; i--) {
suff[i]=min(suff[i+1], f[i]);
}
vector<ll> dp(n+1, INF);
dp[0]=0;
dp[1]=suff[a[1]+1];
for(int i=2; i<=n; i++) {
dp[i]=dp[i-1]+suff[a[i]+1];
int mx=a[i];
int mora=n+5;
for(int j=i-1; j>=1; j--) {
if(a[j+1]<=a[j] && a[j+1]!=0) {
break;
}
if(a[j]+1==a[j+1]) {
if(a[j+1]>=mora) {
break;
}
}
else if(a[j+1]==0) {
if(mora==n+5) {
mora=a[j]+1;
if(mora<=mx) {
break;
}
}
else {
if(mora!=a[j]+1) {
break;
}
}
}
else {
break;
}
mx=max(mx, a[j]);
if(mora==n+5) {
dp[i]=min(dp[i], dp[j-1]+suff[a[i]+1]);
}
else {
dp[i]=min(dp[i], dp[j-1]+f[mora]);
}
}
}
cout << dp[n] << '\n';
return 0;
}
