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 c[] = new int[n-1];
        int ans = 0;

        for (int i = 0; i < n; i++) a[i] = sc.nextInt();
        for (int i = 0; i < n; i++) ans += sc.nextInt();
        for (int i = 0; i < n-1; i++) c[i] = sc.nextInt();
        for (int i = 0; i < n-1; i++) {
            if (a[i] == a[i+1] - 1) {
                ans += c[a[i]-1];
            }
        }

        System.out.println(ans);
        sc.close();

	}
}