using System;

class Buffet{
	static void main(){
      string s = Console.ReadLine();
      int N = int.Parse(s);
      int sum = 0;
      
      s = Console.ReadLine();
      int [] a = int.Parse(s.Split( new char [] {' '}));
      
      s = Console.ReadLine();
      int [] b = int.Parse(s.Split( new char [] {' '}));
      
      s = Console.ReadLine();
      int [] c = int.Parse(s.Split( new char [] {' '}));
      
      for( int i=0; i<N ; i++)
      {
        sum += b[a[i]];
        if(a[i+1] == a[i] + 1 && i != N-1)
        {
       		sum += c[i];
        }
      }
  
      Console.WriteLine(sum);
    }
  
  
}

