import java.util.Scanner;

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];
		int ans = 0;

		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();
		}
		sc.close();

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

System.out.println(ans);
	}
}