#include<iostream>
using namespace std;

int n;
int A[50], C[49];
int sum = 0;
map<int, int> mp;

void solve() {
	for (int i = 0; i < n; ++i) {
		if (i != n-1 && A[i] + 1 == A[i + 1]) {
			sum += C[A[i] - 1];
		}
	}

}
int main() {
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> A[i];
	}

	for (int i = 0, B; i < n; ++i) {
		cin >> B;
		sum += B;
	}

	for (int i = 0; i < n - 1; ++i) {
		cin >> C[i];
	}

	solve();

	cout << sum << '\n';
	return 0;

}