#include <bits/stdc++.h>
using namespace std;
vector<long long int> v;
set<long long int> s1;
set<long long int> s2;
set<string> st2;
vector<long long int> v1;
vector<long long int> v2;
vector<long long int> v3;
vector<long long int> v4;
vector<long long int> v5;
vector<pair<long long int, long long int> > v6;
vector<pair<long long int, long long int> > v16;
vector<string> v7;
vector<string> v8;
vector<char> v9;
vector<double> v11;
list<long long int> l;
int main() {
  long long int n;
  cin >> n;
  long long int a[n], b[n], c[n - 1], d[n + 1];
  for (long long int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (long long int i = 1; i <= n; i++) {
    cin >> b[i];
  }
  for (long long int i = 1; i <= n - 1; i++) {
    cin >> c[i];
  }
  for (long long int i = 1; i <= n + 1; i++) {
    d[i] = 0;
  }
  long long int sum = 0;
  for (long long int i = 1; i <= n; i++) {
    d[a[i]] = 1;
    sum = sum + b[a[i]];
    if (d[a[i] - 1] == 1) {
      sum = sum + c[a[i] - 1];
    }
  }
  cout << sum << endl;
  return 0;
}
