#include <bits/stdc++.h>
using namespace std;
const long long MOD = (long long)1e9 + 7;
const long double PI = acos((long double)-1);
inline int Get_bit(int x, int k) { return (x >> (k - 1)) & 1; }
inline long long Gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long Lcm(long long a, long long b) { return a / Gcd(a, b) * b; }
inline long long Pow(long long n, long long k) {
  long long r = 1;
  for (; k; k >>= 1, n = n * n % MOD) {
    if (k & 1) r = r * n % MOD;
  }
  return r;
}
const int base = 311;
const int N = 2e3 + 10;
int n;
void Solve() {
  int n;
  cin >> n;
  int a[N];
  long long ans = 0;
  int b[N], c[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++) {
    ans += b[a[i]];
    if (i > 1 && a[i] > 1) ans += c[a[i - 1]];
  }
  cout << ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(10);
  Solve();
  return 0;
}
