// 解説みてかいた
#define DEBUG 1
#include <algorithm>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vll = vector<ll>;
using vvll = vector<vll>;
using pll = pair<ll, ll>;
using tll = tuple<ll, ll, ll>;
#define all(v) (v).begin(), (v).end()
#define for1(i, n) for (ll i = 0; i < (n); i++)
#define for2(i, m, n) for (ll i = (m); i < (n); i++)
#define for3(i, m, n, d) for (ll i = (m); i < (n); i += (d))
#define rfor2(i, m, n) for (ll i = (m); i > (n); i--)
#define rfor3(i, m, n, d) for (ll i = (m); i > (n); i += (d))
#define PI 3.1415926535897932384626433832795028841971693993751
#define INF 1111111111111111111LL
#define MOD 1000000007LL  // 10**9 + 7
#define print(...) print_1(__VA_ARGS__)
#define in(...) in_1(__VA_ARGS__)
#if DEBUG
#define dump(...) dump_1(#__VA_ARGS__, __VA_ARGS__)
#define dumpa(...) dumpa_1(#__VA_ARGS__, __VA_ARGS__)
#else
#define dump(...)
#define dumpa(...)
#endif
template <typename Head>
void dump_1(const char* str, Head&& h)
{
    cerr << str << ": " << h << '\n';
}
template <typename Head, typename... Tail>
void dump_1(const char* str, Head&& h, Tail&&... t)
{
    while (*str != ',') {
        cerr << *str++;
    }
    cerr << ": " << h << ' ';
    dump_1(str + 1, t...);
}
template <typename T>
void dumpa_1(const char* str, const T v[], const ll size)
{
    while (*str != ',') {
        cerr << *str++;
    }
    cerr << ": ";
    for1 (i, size) {
        if (i != 0) {
            cerr << ' ';
        }
        cerr << v[i];
    }
    cerr << '\n';
}
template <typename T1, typename T2>
ostream& operator<<(ostream& os, const pair<T1, T2>& v)
{
    os << '(' << v.first << ", " << v.second << ')';
    return os;
}
template <typename T1, typename T2, typename T3>
ostream& operator<<(ostream& os, const tuple<T1, T2, T3>& v)
{
    os << '(' << get<0>(v) << ", " << get<1>(v) << ", " << get<2>(v) << ')';
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ' ';
        }
        os << *it;
    }
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, const set<T>& v)
{
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ' ';
        }
        os << *it;
    }
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, const multiset<T>& v)
{
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ' ';
        }
        os << *it;
    }
    return os;
}
template <typename T1, typename T2>
ostream& operator<<(ostream& os, const map<T1, T2>& v)
{
    os << '{';
    for (auto it = v.begin(); it != v.end(); it++) {
        if (it != v.begin()) {
            os << ", ";
        }
        os << it->first << ':' << it->second;
    }
    os << '}';
    return os;
}
void Yes(void) { cout << "Yes\n"; }
void No(void) { cout << "No\n"; }
void YES(void) { cout << "YES\n"; }
void NO(void) { cout << "NO\n"; }
template <typename T>
bool chmax(T& a, const T& b)
{
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <typename T>
bool chmin(T& a, const T& b)
{
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <typename T>
void vin(vector<T>& v, ll len)
{
    for1 (i, len) {
        cin >> v[i];
    }
}
template <typename Head>
void in_1(Head& h)
{
    cin >> h;
}
template <typename Head, typename... Tail>
void in_1(Head& h, Tail&... t)
{
    cin >> h;
    in_1(t...);
}
template <typename Head>
void print_1(Head&& h)
{
    cout << h << '\n';
}
template <typename Head, typename... Tail>
void print_1(Head&& h, Tail&&... t)
{
    cout << h << ' ';
    print_1(t...);
}
//---------------------------------------------------------
// -- Query Type enum.
enum QUERY_GET { SUM, MAX, MIN };
template <class T = ll>
class SegmentTree {
   private:
    int ARY_SIZE;
    T initVal;
    std::vector<T> ary;
    std::function<T(T&, T&)> merge;

    void init(int n, QUERY_GET qtype)
    {
        switch (qtype) {
            case SUM:
                initVal = 0;
                merge = [](T& l, T& r) { return l + r; };
                break;
            case MAX:
                initVal = std::numeric_limits<T>::lowest();
                merge = [](T& l, T& r) { return (l > r) ? l : r; };
                break;
            case MIN:
                initVal = std::numeric_limits<T>::max();
                merge = [](T& l, T& r) { return (l < r) ? l : r; };
                break;
            default:
                struct INVALID_QUERY_TYPE_ERROR {
                };
                throw INVALID_QUERY_TYPE_ERROR();
                break;
        }
        init(n);
    }
    void init(int n)
    {
        while (ARY_SIZE < n) ARY_SIZE <<= 1;
        ary.resize(ARY_SIZE << 1, initVal);
    }

   public:
    SegmentTree(int n, QUERY_GET qtype) : ARY_SIZE(1) { init(n, qtype); }
    SegmentTree(int n, T initVal, std::function<T(T&, T&)> f)
        : ARY_SIZE(1), initVal(initVal), merge(f)
    {
        init(n);
    }

    // -- a[i] = val;
    inline void update(int i, T val)
    {
        i += ARY_SIZE;
        ary[i] = val;
        while (i > 1) {
            i >>= 1;
            ary[i] = merge(ary[i << 1], ary[(i << 1) + 1]);
        }
    }
    // -- a[i] += val;
    inline void add(int i, T val) { update(i, ary[i + ARY_SIZE] + val); }
    // -- [l, r)
    inline T query(int l, int r)
    {
        if (l >= r) return initVal;
        T vl = initVal, vr = initVal;
        for (l += ARY_SIZE, r += ARY_SIZE; l != r; l >>= 1, r >>= 1) {
            if (l & 1) vl = merge(vl, ary[l++]);
            if (r & 1) vr = merge(ary[--r], vr);
        }
        return merge(vl, vr);
    }
    T operator[](int i) { return ary[i + ARY_SIZE]; }

    void debugShow()
    {
        for (int i = ARY_SIZE; i < ARY_SIZE << 1; ++i)
            std::cerr << ary[i] << " ";
        std::cerr << "\n";
    }
};
using ST = SegmentTree<ll>;
//---------------------------------------------------------
void solve()
{
    ll N;
    in(N);
    vll H(N);
    vll A(N);
    vin(H, N);
    vin(A, N);

    // SegmentTree<ll> st(N + 1, MIN); // 区間最小値
    SegmentTree<ll> st(N + 1, MAX);  // 区間最大値
    // SegmentTree<ll> st(N + 1, SUM); // 区間合計
    for1 (i, N + 1) {
        st.update(i, 0);
    }

    map<ll, ll> hm;
    for1 (i, N) {
        // 区間[l, r)の最大値を取得する
        ll l = 0;
        ll r = H[i];
        ll mi = st.query(l, r);
        chmax(hm[H[i]], mi + A[i]);
        // dump(i, H[i], mi, hm[H[i]]);
        st.update(H[i], hm[H[i]]);
    }
    ll ans = st.query(0, N + 1);
    print(ans);
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(16);
    cerr << fixed << setprecision(16);
    solve();
}


Measured memory_bytes: 19968