flowers

//#include<bits/stdc++.h>
#include<iostream>
#include<vector>
#include<fstream>
#include<algorithm>

#define long long long
#define nln '\n'

const long N = 2*1e5+10;

using namespace std;

// GLobal variables: n, h, a

fstream f1;
long n;
vector<long> h, a;

void data()
{
    f1.open("flowers.inp", ios:: in);
    cin >> n;
    h.resize(n+1, 0);
    a.resize(n+1, 0);
    for (long i = 1; i <= n; ++i)
        cin >> h[i];
    for (long i = 1; i <= n; ++i)
        cin >> a[i];
    f1.close();
}

vector<long> tre;

long get(long id, long lef, long rig, long i, long j)
{
    if (lef > j || rig < i)
        return 0;

    if (lef == rig || (lef >= i && rig <=j))
        return tre[id];

    long mid = (lef + rig)/2;

    return max(get(id*2, lef, mid, i, j), get(id*2+1, mid+1, rig, i, j));
}

void update(long id, long lef, long rig, long hig, long beu)
{
    if (lef == rig)
    {
        tre[id] = beu;
        return;
    }
    long mid = (lef+rig)/2;

    if (hig <= mid)
        update(id*2, lef, mid, hig, beu);
    else
        update(id*2+1, mid+1, rig, hig, beu);

    tre[id] = max(tre[id*2], tre[id*2+1]);
}

void process()
{
    tre.resize(n*4+1, 0);
    for (long k = 1; k <= n; ++k)
    {
        long mav = get(1, 1, n, 1, h[k]-1);
        update(1, 1, n, h[k], mav+a[k]);
    }
    cout << tre[1] << nln;
}

int main()
{
    data();
    process();
    return 0;
}