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];
		
		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;
		int before = -100;
		for(int i=0;i<N;i++) {
			ans += B[A[i]-1];
			if(before + 1 == A[i]) {
				ans+=C[A[i]-2];
			}
			before = A[i];
		}
		
		System.out.println(ans);
		
 	}
}
