#include <iostream>
using namespace std;

int main()
{
  int n, a[20], b[20], c[20], count=0;
  cin >> n;
  for(int i=0; i<n; ++i){
    cin >> a[i];
    --A[i];
  }
  for(int i=0; i<n; ++i) cin >> b[i];
  for(int i=0; i<n-1; ++i) cin >> c[i];
  
  for(int i=0; i<n; ++i){
    count += b[a[i]];
    if(a[i] == a[i-1]+1) count += c[a[i-1]];
  }
  cout << count << endl;
}
