#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 50;
int main() {
  int N;
  int A[MAX_N];
  int B[MAX_N];
  int C[MAX_N];
  cin >> N;
  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];
  int sum = 0;
  for (int i = 0; i < (N); ++i) {
    sum = sum + B[A[i]];
    if (A[i] - 1 == A[i - 1]) {
      sum = sum + C[A[i - 1]];
    }
  }
  printf("%d\n", sum);
  return 0;
}
