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