#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define EB emplace_back
#define MP make_pair
#define all(o) (o).begin(), (o).end()
#define mset(m,v) memset(m,v,sizeof(m))
#define fr(i,n) for(lli i=0;i<n;++i)
#define rep(i,a,b) for(lli i=a;i<=b;++i)
#define per(i,a,b) for(lli i=a;i>=b;i--)
#define remin(a,b) (a=min((a),(b)))
#define remax(a,b) (a=max((a),(b))) 
#define sz(x) (lli)(x).size()
#define endl '\n'
typedef long long lli;        typedef long double ld;
typedef pair<lli,lli> ii;     typedef vector<lli> vi;
typedef vector<ii> vii;       typedef vector<vi> graph;
long long MOD=1000000007;     long double EPS=1e-9;
#define debarr(a,n) cout<<#a<<" : ";for(int i=0;i<n;i++) cerr<<a[i]<<" "; cerr<<endl;
#define debmat(mat,row,col) cout<<#mat<<" :\n";for(int i=0;i<row;i++) {for(int j=0;j<col;j++) cerr<<mat[i][j]<<" ";cerr<<endl;}
#define pr(...) dbs(#__VA_ARGS__, __VA_ARGS__)
template <class S, class T>ostream& operator <<(ostream& os, const pair<S, T>& p) {return os << "(" << p.first << ", " << p.second << ")";}
template <class T>ostream& operator <<(ostream& os, const vector<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const unordered_set<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class S, class T>ostream& operator <<(ostream& os, const unordered_map<S, T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const set<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const multiset<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class S, class T>ostream& operator <<(ostream& os, const map<S, T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T> void dbs(string str, T t) {cerr << str << " : " << t << "\n";}
template <class T, class... S> void dbs(string str, T t, S... s) {int idx = str.find(','); cerr << str.substr(0, idx) << " : " << t << ","; dbs(str.substr(idx + 1), s...);}
template <class T> void prc(T a, T b) {cerr << "["; for (T i = a; i != b; ++i) {if (i != a) cerr << ", "; cerr << *i;} cerr << "]\n";}
lli binpow(lli b,lli p,lli mod){lli ans=1;b%=mod;for(;p;p>>=1){if(p&1)ans=ans*b%mod;b=b*b%mod;}return ans;}

void pre(){

}

template<class node>
struct SegT{
#define mid ((l+r)>>1)
	int n;
	node *t;
	SegT(int n):n(n){t=new node[4*n+10];}
	inline node combine(node a,node b){
		return max(a,b);
	}
	void build(int id,int l,int r){
		if(l==r){
			t[id]=0;
			return;
		}
		build(id<<1,l,mid);
		build(id<<1|1,mid+1,r);
		t[id]=combine(t[id<<1],t[id<<1|1]);
	}
	void update(int id,int l,int r,int pos,lli val){
		if(pos<l||pos>r)return;
		if(l==r){
			remax(t[id],val);return;
		}
		update(id<<1,l,mid,pos,val);
		update(id<<1|1,mid+1,r,pos,val);
		t[id]=combine(t[id<<1],t[id<<1|1]);
	}	
	node query(int id,int l,int r,int lq,int rq){
		if(l>r||lq>r||l>rq)return node(0);
		if(lq<=l&&r<=rq)return t[id];
		return combine(query(id<<1,l,mid,lq,rq),query(id<<1|1,mid+1,r,lq,rq));
	}
#undef mid
};


void solve(){
	lli n;
	cin>>n;
	lli h[n],a[n];
	fr(i,n)cin>>h[i];
	fr(i,n)cin>>a[i];
	SegT<lli> st(n);
	st.build(1,0,n);
	lli dp[n];
	fr(i,n){
		dp[i]=st.query(1,0,n,0,h[i]-1)+a[i];
		st.update(1,0,n,h[i],dp[i]);
	}
	cout<<*max_element(dp,dp+n)<<endl;
}

signed main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("in.txt","r",stdin);//freopen("out.txt","w",stdout);
	pre();lli t=1;//cin>>t;
	for(lli i=1;i<=t;i++){
		//cout<<"Case #"<<i<<": ";
		solve();
	}
}

Measured memory_bytes: 11008