#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n;
  cin >> n;
  vector<int> 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];
  int ans = 0;
  for (long long i = 0; i < (long long)n; ++i) {
    ans += b[a[i]];
    if (a[i - 1] + 1 == a[i]) ans += c[a[i - 1]];
  }
  cout << ans << endl;
}
