#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))
#define BIT_COUNT(bit) (__builtin_popcount(bit))

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline void print_2vec(const std::vector<std::vector<T>> &v) { for (int i = 0; i < v.size(); ++i) { for (int j = 0; j < v[0].size(); ++j) { if (j != 0) { std::cout << " "; } std::cout << std::setw(13) << std::left << v[i][j]; } std::cout << "\n";}}
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }
template<typename T> T &chmin(T &a, const T &b) { return a = std::min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = std::max(a, b); }
template<class T> inline std::vector<T> unique(std::vector<T> v) { sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); return v; }
// 初項s, 交差dのn個の数列の和
long long sum_of_arithmetic_progression(long long s, long long d, long long n) { return n * (2 * s + (n - 1) * d) / 2; }

const int INF = 1 << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = {0, -1, 0, 1}, dx4 = {1, 0, -1, 0};
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;

template <typename T> class SegmentTree {
    const int array_size;        // もとの配列のサイズ
    int n;
    std::vector<T> data;
    std::function<T (T,T)> op;
    T unit;

public:
    enum Mode {
        RangeMinimumQuery,
        RangeMaximumQuery,
        RangeSummationQuery,
    };

    SegmentTree(int array_size, Mode mode) : array_size(array_size) {
        if (mode == RangeMinimumQuery) {
            unit = INT_MAX;
            op = [](T a, T b) { return std::min(a, b); };
        }
        else if (mode == RangeMaximumQuery) {
            unit = 0;
            op = [](T a, T b) { return std::max(a, b); };
        }
        else if (mode == RangeSummationQuery) {
            unit = 0;
            op = [](T a, T b) { return a + b; };
        }
        else {
            assert(false);
        }

        n = 1;
        while (n < array_size) { n *= 2; }   // _n以上の最小の2冪
        data.resize(2 * n - 1, unit);
    }

    template <typename F> SegmentTree(int array_size, T unit, F op) : array_size(array_size), unit(unit), op(op) {
        while (n < array_size) { n *= 2; }   // _n以上の最小の2冪
        data.resize(2 * n - 1, unit);
    }

    T access(int idx) {
        return data[idx + n - 1];
    }

    // array[idx] = x
    // O(log N)
    void update(int idx, T x) {
        assert(0 <= idx and idx < array_size);
        idx += n - 1;   // 木での対象のインデックス
        data[idx] = x;
        while (idx > 0) {
            idx = (idx - 1) / 2;                                    // 親のインデックス
            data[idx] = op(data[idx * 2 + 1], data[idx * 2 + 2]);   // 左の子と右の子
        }
    }

    // op(array[left, right))
    // O(log N)
    T query(int left, int right) {
        assert(0 <= left and left < right and right <= array_size);
        return query(left, right, 0, 0, n);
    }

private:
    // [a, b)の目的値をノードk（区間[l, r]）から検索
    T query(int a, int b, int k, int l, int r) {
        assert(a < b && l < r);
        // 範囲外
        if (r <= a || b <= l) {
            return unit;
        }
        // 完全に含む
        if (a <= l && r <= b) {
            return this->data[k];
        }
            // 一部含む
        else {
            T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);    // 左の子
            T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);    // 右の子
            return op(vl, vr);
        }
    }
};


int main() {
    cin.tie(0);
	ios::sync_with_stdio(false);

	int N;
	cin >> N;
	V<int> H(N), A(N);
	FOR(i, 0, N) {
	    cin >> H[i];
	}
    FOR(i, 0, N) {
        cin >> A[i];
    }

    SegmentTree<LL> st(2 * 100000 + 100, SegmentTree<LL>::RangeMaximumQuery);
	FOR(i, 0, N) {
	    int h = H[i];
	    int a = A[i];
	    LL v = st.query(0, h) + a;
	    st.update(h, max(st.access(h), v));
	}

	print(st.query(0, 2 * 100000 + 100));

	return 0;
}

Measured memory_bytes: 5888