#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  int a[N], b[N], c[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;
  sum = sum + b[a[0]];
  for (int i = 1; i < N; i++) {
    if (a[i] - a[i - 1] == 1) {
      sum = sum + b[a[i]] + c[a[i - 1]];
    } else {
      sum = sum + b[a[i]];
    }
  }
  cout << sum << endl;
}
