// HTTF.cpp : このファイルには 'main' 関数が含まれています。プログラム実行の開始と終了がそこで行われます。
//

#include "bits/stdc++.h"
#define YES "YES"
#define NO "NO"
#define YESNO OUT(three(solve(),YES,NO))
#define ECHO OUT(solve())
#define three(A,B,C) ((A)?(B):(C))
#define FOR(i,a,b)  for(LL i=(a);i< (LL)(b);i++)
#define EFOR(i,a,b) for(LL i=(a);i<=(LL)(b);i++)
#define RFOR(i,a,b) for(LL i=(a);i>=(LL)(b);i--)
#define REP(i,b) FOR(i,zero,b)
#define EREP(i,b) EFOR(i,zero,b)
#define RREP(i,b) RFOR(i,b,zero)
#define ALL(c) c.begin(),c.end()
#define UNIQUE(c) sort(ALL(c));c.erase(unique(ALL(c)),c.end())
#define MAX(c) (*max_element(ALL(c)))
#define MIN(c) (*min_element(ALL(c)))
#define MP make_pair
#define FI first
#define SE second
#define SI(x) (LL(x.size()))
#define PB push_back
#define DEBUG(a) OUT(a)
#define DEBUG2(a,b) OUT2(a,b)
#define cat cout << __LINE__ << endl
#define OUT(a) cout << (a) << endl
#define OUT2(a,b) cout << (a) <<" "<<(b) << endl
#define zero 0LL
#define int LL
#define pb emplace_back
#define eb pb

using namespace std;
template<typename T> inline void maximize(T &a, T b) { a = max(a, b); }
template<typename T> inline void minimize(T &a, T b) { a = min(a, b); }
template<typename T> inline bool middle(T a, T b, T c) { return b <= a && a <= c; }
template<class T> inline bool MX(T &l, const T &r) { return l < r ? l = r, 1 : 0; }
template<class T> inline bool MN(T &l, const T &r) { return l > r ? l = r, 1 : 0; }
typedef long long LL;
typedef double ld;
typedef int ut;
typedef vector<ut> VI;
typedef vector<VI> VII;
typedef pair<ut, ut> pr;
typedef pair<ut, pr> ppr;
typedef vector<pr> Vpr;
typedef vector<ppr> Vppr;
typedef priority_queue<pr, Vpr, greater<pr> > PQ;
inline void outputVI(VI x) { REP(i, SI(x)) { cout << three(i, " ", "") << x[i]; }OUT(""); }
const int SIZE1 = 5e5 + 1000;
const int SIZE2 = 3010;
const int SIZE3 = 330;
const int SIZE = SIZE1;
const int MAPSIZE = 40;
const LL p = 7 + 1e9;
const LL INF = 1LL << 60;
const long double EPS = 1e-7;
typedef pair<ld, ut> pld;
template <typename T, typename E>
struct SegmentTree {
	typedef function<T(T, T)> F;
	typedef function<T(T, E)> G;
	int n;
	F f;
	G g;
	T d1;
	vector<T> dat;
	SegmentTree(int n_, F f, G g, T d1,
		vector<T> v = vector<T>()) {
		this->f = f;
		this->g = g;
		this->d1 = d1;
		init(n_);
		if (n_ == (int)v.size()) build(n_, v);
	}
	void init(int n_) {
		n = 1;
		while (n < n_) n *= 2;
		dat.clear();
		dat.resize(2 * n - 1, d1);
	}
	void build(int n_, vector<T> v) {
		for (int i = 0; i < n_; i++) dat[i + n - 1] = v[i];
		for (int i = n - 2; i >= 0; i--)
			dat[i] = f(dat[i * 2 + 1], dat[i * 2 + 2]);
	}
	void update(int k, E a) {
		k += n - 1;
		dat[k] = g(dat[k], a);
		while (k > 0) {
			k = (k - 1) / 2;
			dat[k] = f(dat[k * 2 + 1], dat[k * 2 + 2]);
		}
	}
	T query(int a, int b, int k, int l, int r) {
		if (r <= a || b <= l) return d1;
		if (a <= l && r <= b) return dat[k];
		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 f(vl, vr);
	}
	T query(int a, int b) {
		return query(a, b, 0, 0, n);
	}
};
#define endl "\n" //インタラクティブでは消す
ut N, M, K, L, Q, D, H, W;
// ut A,B,C,D,E,F,G,H,I,J,O,P,Q,R,T,U;
VI edges[SIZE];
LL vals[SIZE], maps2[SIZE2][SIZE2], answer = zero;
LL maps[SIZE2][SIZE2];
LL DP[SIZE][2];
bool finished[SIZE][2];
LL A[SIZE];
LL h[SIZE];
LL solve() {
	cin >> N;
	Vpr v;
	REP(i, N) {
		cin >> h[i];
		v.pb(h[i], i);
	}
	REP(i, N) {
		cin >> A[i];
	}
	SegmentTree<int, int> rmq(N+5,
		[](int a, int b) {return max(a, b); },
		[](int a, int b) {return b; },
		0LL);
	LL ans = 0;
	sort(ALL(v));
	REP(k, N) {
		int i = v[k].second;
		LL val = rmq.query(0, i) + A[i];
		MX(ans, val);
	//	cout << i + 1 << " " << val << endl;
		rmq.update(i,val);
	}
	cout << ans << endl;
	return 0;
}




//!!!!!!!!!!!!!!!!!!!実装を詰める!!!!!!!!!!!!!!!!!!!!!!!!!
signed main() {

	ios_base::sync_with_stdio(false);
	cout << fixed << setprecision(0);
	solve();
	cin >> N;
	return 0;

}

Measured memory_bytes: 26348