#include <bits/stdc++.h>
using namespace std;
int MOD = 1000000007;
int main(void) {
  int N, ans = 0;
  cin >> N;
  int A[N + 10], B[N + 10], C[N + 10];
  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++) {
    if (i != 0 && A[i - 1] + 1 == A[i]) {
      ans += C[A[i - 2]];
    }
    ans += B[A[i] - 1];
  }
  cout << ans << endl;
}
