#include <bits/stdc++.h>
using namespace std;
long long N;
long long A[30], B[30], C[30];
int main() {
  cin >> N;
  for (long long i = 0; i < N; i++) {
    cin >> A[i];
  }
  for (long long i = 0; i < N; i++) {
    cin >> B[i];
  }
  for (long long i = 0; i < N - 1; i++) {
    cin >> C[i];
  }
  long long sumi = 0;
  for (long long i = 0; i < N; i++) {
    long long food = A[i] - 1;
    sumi += B[food];
    if (i < N - 1 && A[i] < A[i + 1]) {
      sumi += C[food];
    }
  }
  cout << sumi << endl;
}
