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 ans = 0;
        for (int i=0;i<n;i++){
            ans+=b[a[i]-1];
            if (i!=n-1&&a[i+1]==a[i]+1)ans+=c[a[i]-1];
        }
        System.out.println(ans);
    }
}
