#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const deque<T> &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> void Max(T &m, const T q) { if (m < q) m = q; }
template<typename T> void Min(T &m, const T q) { if (m > q) m = q; }
template<typename T1, typename T2> pair<T1, T2> operator+(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;

int N;
vector<int> h;
vector<lint> a;

template <typename T>
struct SegTree
{
    int N;
    int head;
    vector<T> x;
    T defaultT;
    using func = function<T(const T&, const T&)>;
    func tree_update;

    T _query_search(int begin, int end, int pos, int l, int r)
    {
        if (r <= begin || l >= end) return defaultT;
        if (l >= begin && r <= end) return x[pos];
        T v_l = _query_search(begin, end, 2*pos+1, l, (l+r)/2);
        T v_r = _query_search(begin, end, 2*pos+2, (l+r)/2, r);
        return tree_update(v_l, v_r);
    }

    SegTree(int N, T val_default, func f) : N(N), defaultT(val_default), tree_update(f)
    {
        int N_tmp = 1;
        while (N_tmp < N) N_tmp <<= 1;
        x = vector<T>(N_tmp*2, defaultT);
        head = N_tmp - 1;
    }

    void update(int pos, T val)
    {
        pos += head;
        x[pos] = val;
        while (pos)
        {
            pos = (pos - 1) / 2;
            x[pos] = tree_update(x[pos*2+1], x[pos*2+2]);
        }
    }
    T query(int begin, int end)
    {
        return _query_search(begin, end, 0, 0, (int)x.size() / 2);
    }
};

int main()
{
    cin >> N;
    h.resize(N);
    a.resize(N);
    cin >> h >> a;

    SegTree<lint> rMq(N + 1, 0, [](lint a, lint b) { return max(a, b); });

    lint res = 0;
    REP(i, N)
    {
        lint tmp = rMq.query(0, h[i]) + a[i];
        Max(res, tmp);
        rMq.update(h[i], tmp);
    }
    cout << res << endl;
}


Measured memory_bytes: 6656