// Slower C++ solution:
#include <algorithm>

#include <bitset>

#include <cassert>

#include <cmath>

#include <functional>

#include <iomanip>

#include <iostream>

#include <map>

#include <queue>

#include <unordered_map>

#include <vector>

#include <string.h>

#include <set>



using namespace std;



#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl



template<class T> void printvec(const vector<T>& v) {

  for (auto x : v) { cout << x << " "; }

  cout << endl;

}

template<class T> void printtree(const vector< vector<T> >& tree) {

  for (long long i = 0; i < tree.size(); ++i) {

    cout << i + 1 << ": "; printvec(tree[i]);

  }

}

template<class T, class U> void printmap(const map<T, U>& mp) {

  for (auto x : mp) { cout << x.first << "=>" << x.second << endl; }

}



template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }



#define rep(i, n) for(ll i = 0; i < n; ++i)

#define all(s) s.begin(), s.end()

#define sz(x) (ll)(x).size()

#define fr first

#define sc second

#define mp make_pair

#define pb push_back

#define eb emplace_back



typedef long long ll;

typedef unsigned long long ull;

typedef pair<ll, ll> P;

typedef tuple<ll, ll, ll> triple;

typedef double D;

typedef vector<ll> vl;

typedef vector<P> vp;



const ll INF = 1e9;

const ll MOD = 1000000007;  // 1e9 + 7



// Segment Tree

template <typename T>

class SegTree {

public:

  SegTree(int _n) {

    n = 1;

    while (n < _n) { n *= 2; }

    dat = vector<T>(2 * n - 1);

  }



  void update(int k, T a) {

    k += n - 1;

    dat[k] = a;

    while (k > 0) {

      k = (k - 1) / 2;

      dat[k] = max(dat[k * 2 + 1], dat[k * 2 + 2]);

    }

  }



  // Calculate the max of [a, b)

  T query(int a, int b) {

    return _query(a, b, 0, 0, n);

  }



  // Calculate the max of [a, b)

  // k is the index (dat[k]). This is matched to [l, r)

  T _query(int a, int b, int k, int l, int r) {

    // The intersection of [a, b) and [r, l) is blank.

    if (r <= a || b <= l) { return 0; }



    if (a <= l && r <= b) {  // [r, l) is completely included in [a, b)

      return dat[k];

    } else {

      T vl = _query(a, b, k * 2 + 1, l, (l + r) / 2);

      T vr = _query(a, b, k * 2 + 2, (l + r) / 2, r);

      return max(vl, vr);

    }

  }



private:

  int n; // The size of source data. The power of 2.

  vector<T> dat; // The data. The size if 2*n-1. The last n elements(dat[n..2*n-2]) are leaves(source data). The first n-1 elements are nodes.

};



// int main(int argc, char** argv) {

//   int arr[] = { 1, 3, 2, 7, 9, 11 };

//   int n = 6;

//

//   SegTree<int> st(n);

//   rep(i, n) {

//     st.update(i, arr[i]);

//   }

//

//   cout << st.query(1, 5) << endl;

//   cout << st.query(0, 4) << endl;

//   cout << st.query(3, 5) << endl;

// }



const ll N = 2e5 + 5;



int main(int argc, char** argv) {

  cin.tie(NULL);

  cout.tie(NULL);

  ios_base::sync_with_stdio(false);

  //cout << setprecision(10) << fixed;



  ll n;

  cin >> n;

  vector<ll> h(n);

  rep(i,n) {

    cin >> h[i];

  }

  vector<ll> a(n);

  rep(i,n) {

    cin >> a[i];

  }

  SegTree<ll> st(N);

  rep(i,n) {

    ll nh = h[i];

    ll na = a[i];

    ll pre = st.query(0, nh);

    if (st.query(nh, nh+1) < pre+na) {

      st.update(nh, pre + na);

    }

  }

  ll ans = st.query(0, N); // max of [0, N-1]

  cout << ans << endl;

}


// Faster C++ solution for the same problem (measured speedup: 5.220607020956983x):
#include <algorithm>

#include <bitset>

#include <cassert>

#include <cmath>

#include <functional>

#include <iomanip>

#include <iostream>

#include <map>

#include <queue>

#include <unordered_map>

#include <vector>

#include <string.h>

#include <set>



using namespace std;



#define COUT(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << endl



template<class T> void printvec(const vector<T>& v) {

  for (auto x : v) { cout << x << " "; }

  cout << endl;

}

template<class T> void printtree(const vector< vector<T> >& tree) {

  for (long long i = 0; i < tree.size(); ++i) {

    cout << i + 1 << ": "; printvec(tree[i]);

  }

}

template<class T, class U> void printmap(const map<T, U>& mp) {

  for (auto x : mp) { cout << x.first << "=>" << x.second << endl; }

}



template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }



#define rep(i, n) for(ll i = 0; i < n; ++i)

#define all(s) s.begin(), s.end()

#define sz(x) (ll)(x).size()

#define fr first

#define sc second

#define mp make_pair

#define pb push_back

#define eb emplace_back



typedef long long ll;

typedef unsigned long long ull;

typedef pair<ll, ll> P;

typedef tuple<ll, ll, ll> triple;

typedef double D;

typedef vector<ll> vl;

typedef vector<P> vp;



const ll INF = 1e9;

const ll MOD = 1000000007;  // 1e9 + 7



// Segment Tree

template <typename T>

class SegTree {

public:

  SegTree(int _n) {

    n = 1;

    while (n < _n) { n *= 2; }

    dat = vector<T>(2 * n - 1);

  }



  void update(int k, T a) {

    k += n - 1;

    dat[k] = a;

    while (k > 0) {

      k = (k - 1) / 2;

      dat[k] = max(dat[k * 2 + 1], dat[k * 2 + 2]);

    }

  }



  // Calculate the max of [a, b)

  T query(int a, int b) {

    return _query(a, b, 0, 0, n);

  }



  // Calculate the max of [a, b)

  // k is the index (dat[k]). This is matched to [l, r)

  T _query(int a, int b, int k, int l, int r) {

    // The intersection of [a, b) and [r, l) is blank.

    if (r <= a || b <= l) { return 0; }



    if (a <= l && r <= b) {  // [r, l) is completely included in [a, b)

      return dat[k];

    } else {

      T vl = _query(a, b, k * 2 + 1, l, (l + r) / 2);

      T vr = _query(a, b, k * 2 + 2, (l + r) / 2, r);

      return max(vl, vr);

    }

  }



private:

  int n; // The size of source data. The power of 2.

  vector<T> dat; // The data. The size if 2*n-1. The last n elements(dat[n..2*n-2]) are leaves(source data). The first n-1 elements are nodes.

};



// int main(int argc, char** argv) {

//   int arr[] = { 1, 3, 2, 7, 9, 11 };

//   int n = 6;

//

//   SegTree<int> st(n);

//   rep(i, n) {

//     st.update(i, arr[i]);

//   }

//

//   cout << st.query(1, 5) << endl;

//   cout << st.query(0, 4) << endl;

//   cout << st.query(3, 5) << endl;

// }



const ll N = 2e5 + 5;



int main(int argc, char** argv) {

  cin.tie(NULL);

  cout.tie(NULL);

  ios_base::sync_with_stdio(false);

  //cout << setprecision(10) << fixed;



  ll n;

  cin >> n;

  vector<P> p(n); // height, i

  rep(i,n) {

    cin >> p[i].first;

    p[i].second = i;

  }

  sort(all(p));



  vector<ll> a(n);

  rep(i,n) {

    cin >> a[i];

  }



  SegTree<ll> st(n);

  rep(i,n) {

    ll j = p[i].second; // index

    ll pre = st.query(0, j); // maximum value in [0, j)

    st.update(j, pre + a[j]);

  }

  ll ans = st.query(0, n); // max of [0, N-1]

  cout << ans << endl;

}