#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n;
  int a[20], b[20], c[20];
  cin >> n;
  string line;
  getline(cin, line);
  istringstream issA(line);
  for (int i = 0; i < n; ++i) {
    issA >> a[i];
  }
  getline(cin, line);
  istringstream issB(line);
  for (int i = 0; i < n; ++i) {
    issB >> b[i];
  }
  getline(cin, line);
  istringstream issC(line);
  for (int i = 0; i < n - 1; ++i) {
    issC >> c[i];
  }
  int prev = -10, cur, score = 0;
  for (int i = 0; i < n; ++i) {
    cur = a[i];
    score += b[cur];
    if (prev == cur - 1) {
      score += c[prev];
    }
  }
  cout << score << endl;
  return 0;
}
