#include<bits/stdc++.h>
#define rep(i,n) for(int i=1;i<=(n);i++)
using namespace std;

int main(){
  int n,s=0;
  cin >> n;
  int a[n],b[n],c[n-1];
  rep(i,n)	cin >> a[i];
  rep(i,n)	cin >> b[i];
  rep(i,n-1) cin >> c[i];
  
  rep(i,n){
  	s+=b[a[i]];
    if(a[i]+1==a[i+1])
      s+=c[a[i]];
  
  }
  cout << s;
  
  
  return 0;

}