#include <bits/stdc++.h>
using namespace std;
int getmd(int a, int b, int c, int d) { return abs(a - c) + abs(b - d); }
int main() {
  int n, ans(0), x(-1);
  cin >> n;
  int a[n], b[n], c[n - 1];
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < n; i++) cin >> b[i];
  for (int i = 0; i < n - 1; i++) cin >> c[i];
  for (int i = 0; i < n; i++) {
    ans += b[a[i] - 1];
    if (a[i] == x) {
      ans += c[a[i] - 2];
    } else {
      x = a[i] + 1;
    }
  }
  cout << ans << endl;
  return 0;
}
