import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int menuNum = sc.nextInt();
		int[] menuArray = new int[menuNum];
		int[] manzokuArray = new int[menuNum];
		int[] manpukuArray = new int[menuNum - 1];
		int lastManzoku = 0;
		boolean lastMem = false;
		int count = 0;

		for (int i = 0; i < menuNum; i++) {
			menuArray[i] = sc.nextInt();
		}

		for (int i = 0; i < menuNum; i++) {
			manzokuArray[i] = sc.nextInt();
		}

		for (int i = 0; i < menuNum - 1; i++) {
			manpukuArray[i] = sc.nextInt();
		}

		for (int i = 1; i <= menuNum; i++) {
			lastManzoku += manzokuArray[menuArray[i - 1] - 1];
			lastMem = false;
			if (i != 1) {

				if (menuArray[i - 2] == (menuArray[i-1] - 1)) {
					lastMem = true;
				} else {
					lastMem = false;
				}
			} else {

			}
			if (lastMem) {
				lastManzoku += manpukuArray[count];
				count++;
			}
		}

		System.out.println(lastManzoku);

		// Scannerクラスのインスタンスをクローズ
		sc.close();
	}
}