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

	}

}
