#include<bits/stdc++.h>
#include<iostream>
#include<cmath>
#include<vector>
#include<string>
#include<queue>
#include<set>
#include<map>
#include<algorithm>
#include<functional>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pullull;
typedef pair<ll, int> plli;
typedef pair<int, pii> pipii;
typedef vector<vector<int> > mati;
typedef vector<vector<double> > matd;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;
typedef vector<vector<vector<bool>>> vvvb;

#define FOR(i,x,y) for(ll i=(ll)x; i<(ll)y; ++i)
#define REP(i,y) FOR(i, 0, y)

template <typename T>
void vec_print(vector<T> VEC){
  REP(i, VEC.size()){
    cout << VEC[i] << " ";
  }
  cout << "\n";
};

template <typename T>
void mat_print(vector<vector<T> > MAT){
  REP(i, MAT.size()){
    REP(j, MAT[i].size()){
      cout << MAT[i][j] << " ";
    }
    cout << "\n";
  }
};

template <typename CLASS1, typename CLASS2>
class HOGE{
  public:
    CLASS1 key;
    CLASS2 value;
    HOGE(void){
      return;
    };
    HOGE(CLASS1 key, CLASS2 value){
      this->key = key;
      this->value = value;
    };
    ~HOGE(void){
      return;
    };

    void print(void){
      cout << "key : " << key << ", value : " << value << "\n";
      return;
    };
    
    bool operator==(const HOGE &obj){
      return (this->value == obj.value);
    };
    bool operator<(const HOGE &obj){
      return (this->value < obj.value);
    };
    bool operator>(const HOGE &obj){
      return (this->value > obj.value);
    };
};

template <typename CLASS1>
class Binary_Index_Tree{
  private:
    CLASS1 n;
    // [1, n]
    vector<CLASS1> bit;

  public:
    Binary_Index_Tree(CLASS1 n_){
      bit.resize(n_+1, 0);
      n = n_+1;
      return;
    };

    ~Binary_Index_Tree(void){
      return;
    };

    CLASS1 submax(CLASS1 i){
      if(i < -1 || n <= i){
        fprintf(stderr, "Binary_Index_Tree Sum Position Error\n");
        exit(0);
      }
      CLASS1 s=0;
      i += 1;
      while(i>0){
        s = max(s, bit[i]);
        i -= i&(-i);
      }
      return s;
    };

    void update(CLASS1 i, CLASS1 x){
      if(i < 0 || n <= i){
        fprintf(stderr, "Binary_Index_Tree Update Position Error\n");
        exit(0);
      }
      i += 1;
      while(i <= n){
        bit[i] = max(bit[i], x);
        i += i&(-i);
      }
      return;
    };
    
};


constexpr int INF = (1<<30);
constexpr ll INFLL = 1LL<<62;
constexpr long double EPS = 1e-12;
constexpr ll MOD = (ll)((1E+9)+7);

int main(){
  cin.tie(0); // cut the cin and cout (default, std::flush is performed after std::cin)
  ios::sync_with_stdio(false); // cut the iostream and stdio (DON'T endl; BUT "\n";)

  ll N;
  cin >> N;
  Binary_Index_Tree<ll> que(N+1);
  vll dp(N+1, 0), h(N), a(N);
  REP(i, N) cin >> h[i];
  REP(i, N) cin >> a[i];


  REP(i, N){
    dp[i] = que.submax(h[i]-1) + a[i];
    que.update(h[i], dp[i]);
  }

  ll ans = 0;
  REP(i, N+1){
    ans = max(ans, dp[i]);
  }

  cout << ans << "\n";

  return 0;
}


Measured memory_bytes: 6528