#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, b;
  int sum = 0;
  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;
    sum += b;
  }
  for (int i = 0; N - 1; i++) {
    cin >> C[i];
  }
  for (int i = 0; i < N - 1; i++) {
    if (A[i] + 1 == A[i + 1]) {
      sum += C[A[i] - 1];
    }
  }
  cout << sum << '\n';
}
