#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, e = 0;
  cin >> a;
  int f = INT_MAX;
  int b[a];
  int c[a];
  int d[a];
  for (int i = 0; i < (int)(a); ++i) {
    cin >> b[i];
  }
  for (int i = 0; i < (int)(a); ++i) {
    cin >> c[i];
  }
  for (int i = 0; i < (int)(a - 1); ++i) {
    cin >> d[i];
  }
  for (int i = 0; i < (int)(a); ++i) {
    e += c[b[i] - 1];
    if (f == b[i] - 1) e += d[i - 1];
    f = b[i];
  }
  cout << e;
}
