#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  vector<long long> arra(n);
  vector<long long> arrb(n);
  vector<long long> arrc(n);
  long long total = 0;
  long long temp = 0;
  for (int i = 0; i < n; ++i) {
    cin >> arra[i];
  }
  for (int i = 0; i < n; ++i) {
    cin >> arrb[i];
  }
  for (int i = 0; i < n - 1; ++i) {
    cin >> arrc[i];
  }
  for (int x = 0; x < n; ++x) {
    if (temp == (arra[x] - 1)) {
      temp = arra[x];
      total += (arrb[temp - 1] + arrc[temp - 2]);
    } else {
      temp = arra[x];
      total += arrb[temp - 1];
    }
  }
  cout << total;
}
