// **** WHEN THE GOING GETS TOUGH, THE TOUGH GETS GOING. ****

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define ll long long int
#define ull unsigned long long int
#define ld long double
#define ordered_set tree < ll ,  null_type ,  less<ll> ,  rb_tree_tag ,  tree_order_statistics_node_update >
//added two more functions to set
//(1)*(set.find_by_order(k))[kth element in the sorted set] 
//(2)set.order_of_key(k)[count of elements strictly less than k]

typedef vector< int > vi;
typedef vector< ll > lvi;
typedef vector< vi > vvi;
typedef vector< lvi > lvvi;
typedef pair< int,int > ii;
typedef pair< ll,ll > lii;
typedef vector<ii> vii;
typedef vector<lii> lvii;

#define min_prq(t) priority_queue<t,vector<t>,greater<t>>
#define max_prq(t) priority_queue<t>
#define pb push_back
#define all(c) (c).begin(),(c).end()
#define tr(c,i) for(auto i = (c).begin(); i != (c).end(); i++)//remember i is an iterator
#define present(c,x) ((c).find(x) != (c).end())//for sets,maps,multimaps
#define cpresent(c,x) (find(all(c),x) != (c).end())//for vectors
#define tc(t) int (t); cin>>(t);while((t)--)
#define ff first
#define ss second
#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }
void err(istream_iterator<string> it) {}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
	cerr << *it << " is " << a << endl;
	err(++it, args...);
}

//-----------------------------------------------------------------------------------------------------------------------------------------------------------------
#define mod 1000000007
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------

ll mod_sum() { return 0LL; }
template<typename T, typename... Args>
T mod_sum(T a, Args... args) { return ((a + mod_sum(args...))%mod + mod)%mod; }

ll mod_product() { return 1LL; }
template<typename T, typename... Args>
T mod_product(T a, Args... args) { return (a*mod_product(args...))%mod; }
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------

class SegmentTrees
{
	lvi st;
	ll n;
public:
	SegmentTrees(ll N)
	{
		n=N;
		st.assign(4*n,0);
	}
	ll lfc(ll x) {return x<<1LL;}
	ll rgc(ll x) {return (x<<1LL)+1;}
	void update(ll idx,ll val,ll left,ll right,ll pos=1)
	{
		if(left==right)
		{
			st[pos]=val;
			// error(pos,st[pos]);
		}
		else
		{
			ll mid=(left+right)/2;
			if(idx<=mid)
			{
				update(idx,val,left,mid,lfc(pos));
			}
			else
			{
				update(idx,val,mid+1,right,rgc(pos));
			}
			st[pos]=max(st[lfc(pos)],st[rgc(pos)]);
		}
	}
	ll get_max(ll l,ll r,ll left,ll right,ll pos=1)
	{
		if(l>r) return 0;
		if(l==left && r==right) return st[pos];
		ll mid=(left+right)/2;
		return max(get_max(l,min(r,mid),left,mid,lfc(pos)),get_max(max(mid+1,l),r,mid+1,right,rgc(pos)));
	}
};

signed main()
{
	ios_base::sync_with_stdio(false);
    cin.tie(NULL);	
	ll n;
	cin>>n;
	lvi h(n),a(n);
	for (int i = 0; i < n; ++i)
	{
		cin>>h[i];
	}
	for (int i = 0; i < n; ++i)
	{
		cin>>a[i];
	}
	SegmentTrees sgt(n+1);
	ll ans=0;
	for (int i = n-1; i >=0; --i)
	{
		ll dp=a[i]+sgt.get_max(h[i]+1,n,1,n);
		// error(i,dp);
		sgt.update(h[i],dp,1,n);
		ans=max(ans,dp);
	}
	cout<<ans<<endl;
	return 0;
}

Measured memory_bytes: 9600