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