#include <iostream>
#include <vector>
using namespace std;

int main() {
	int N, ans = 0;
	cin >> N;
	vector<int> A(N), B(N), C(N - 1);
	for (int& i : A) cin >> i;
	for (int& i : B) cin >> i;
	for (int& i : C) cin >> i;
	for (int& i : A) ans += B[i - 1];
	for (int i = 1; i < N; ++i) {
		if (1 + A[i - 1] == A[i]) ans += C[A[i - 1] - 1];
	}
	cout << ans;
}