#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main()
{
    int n;
    cin >> n;
    vector<int> a(n), b(n), c(n - 1);
    rep(i, n) cin >> a[i];
    rep(i, n) cin >> b[i];
    rep(i, n - 1) cin >> c[i];
    int ans = 0;
    rep(i, n)
    {
        ans += b[a[i] - 1];
        if (i > 0 && a[i - 1] - 1 >= 0 && a[i - 1] - 1 <= n - 2)
            ans += c[a[i - 1] - 1];
    }
    cout << ans << endl;
    return 0;
}