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