import java.util.*;
public class Main{
    public static void main(String [] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int[] A = new int[N];
        int[] B = new int[N];
        int[] C = new int[N-1];
        for(int i = 0; i < N; i++)A[i] = sc.nextInt();
        for(int i = 0; i < N; i++)B[i] = sc.nextInt();
        for(int i = 0; i < N-1; i++)C[i] = sc.nextInt();

        int P = B[A[0]-1];
        for(int i = 1; i < N; i++){
            if(A[i-1]+1 == A[i]){
                P = P+B[A[i]-1]+C[A[i]-1];
            }else{
                P = P+B[A[i]-1];
            }
        }
        System.out.println(P);
    }
}