#include <bits/stdc++.h>
using namespace std;
template <typename T>
void debugV(const vector<T> v) {
  (void)v;
}
const unsigned int BIT_FLAG_0 = (1 << 0);
const unsigned int BIT_FLAG_1 = (1 << 1);
const unsigned int BIT_FLAG_2 = (1 << 2);
const unsigned int BIT_FLAG_3 = (1 << 3);
const unsigned int BIT_FLAG_4 = (1 << 4);
const unsigned int BIT_FLAG_5 = (1 << 5);
const unsigned int BIT_FLAG_6 = (1 << 6);
const unsigned int BIT_FLAG_7 = (1 << 7);
const unsigned int BIT_FLAG_8 = (1 << 8);
const unsigned int BIT_FLAG_9 = (1 << 9);
const unsigned int BIT_FLAG_10 = (1 << 10);
const unsigned int BIT_FLAG_11 = (1 << 11);
constexpr long long INF = 0x3f3f3f3f3f3f3f3f;
constexpr double PI = 3.14159265358979323846;
constexpr int MOD = 1000000007;
void Main() {
  long long n;
  cin >> n;
  vector<long long> a(n), b(n), c(n - 1);
  for (long long i = 0; i < (long long)(n); i++) {
    cin >> a[i];
    a[i]--;
  }
  for (long long i = 0; i < (long long)(n); i++) {
    cin >> b[i];
  }
  for (long long i = 0; i < (long long)(n - 1); i++) {
    cin >> c[i];
  }
  long long ans = 0;
  long long before = -1;
  for (long long i = 0; i < (long long)(n); i++) {
    ans += b[a[i]];
    if (before == a[i] - 1) {
      ans += c[a[i] - 1];
    }
    before = a[i];
  }
  cout << (ans) << endl;
  ;
}
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(15);
  Main();
}
