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

	}

}
