#include<iostream>
#include<vector>
#define for for(int i=1;i<=n;i++)
using namespace std;

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