#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  int A[30];
  int B[30];
  int C[30];
  cin >> N;
  for (int i = 0; i < N; ++i) cin >> A[i];
  for (int k = 0; k < N; ++k) cin >> B[k];
  for (int j = 0; j < (N - 1); ++j) cin >> C[j];
  int sum = 0;
  for (int q = 0; q < N; q++) {
    if (A[q + 1] - A[q] == 1) {
      int p = A[q];
      sum += C[p];
    }
    sum += B[q];
  }
  cout << sum << endl;
}
