using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using System.Text;

namespace AtCoder
{
	public class Program
	{
		static void Main()
		{
			var cin = new Scanner();
			int n = cin.Int();
			var h = cin.ArrayInt(n, -1);
			var a = cin.ArrayLong(n);

			var seg = new SegmentTree<long>(
				n,
				0,
				(x, y) => Math.Max(x, y));

			for (int i = 0; i < n; i++) {
				long max = seg.Query(0, h[i] + 1);
				seg.Update(h[i], max + a[i]);
			}

			long ans = seg.Query(0, n);
			Console.WriteLine(ans);
		}
	}

	public class SegmentTree<T>
	{
		private readonly int n_;
		private readonly T unit_;
		private readonly T[] tree_;
		private readonly Func<T, T, T> merge_;

		public int Count { get; }
		public T Top => tree_[1];

		public SegmentTree(int count, T unit, Func<T, T, T> merge)
		{
			merge_ = merge;
			unit_ = unit;

			Count = count;
			n_ = 1;
			while (n_ < count) {
				n_ <<= 1;
			}

			tree_ = new T[n_ << 1];
			for (int i = 0; i < tree_.Length; i++) {
				tree_[i] = unit;
			}
		}

		public SegmentTree(T[] src, T unit, Func<T, T, T> merge)
			: this(src.Length, unit, merge)
		{
			for (int i = 0; i < src.Length; ++i) {
				tree_[i + n_] = src[i];
			}

			for (int i = n_ - 1; i > 0; --i) {
				tree_[i] = merge_(tree_[i << 1], tree_[(i << 1) + 1]);
			}
		}

		public T this[int index]
		{
			get { return tree_[index + n_]; }
			set { Update(index, value); }
		}

		public void Update(int index, T val)
		{
			if (index >= Count) {
				return;
			}

			index += n_;
			tree_[index] = val;
			index >>= 1;
			while (index != 0) {
				tree_[index] = merge_(tree_[index << 1], tree_[(index << 1) + 1]);
				index >>= 1;
			}
		}

		public T Query(int left, int right)
		{
			if (left > right || right < 0 || left >= Count) {
				return unit_;
			}

			int l = left + n_;
			int r = right + n_;
			T valL = unit_;
			T valR = unit_;
			while (l < r) {
				if ((l & 1) != 0) {
					valL = merge_(valL, tree_[l]);
					++l;
				}
				if ((r & 1) != 0) {
					--r;
					valR = merge_(tree_[r], valR);
				}

				l >>= 1;
				r >>= 1;
			}

			return merge_(valL, valR);
		}
	}

	public class HashMap<TKey, TValue> : Dictionary<TKey, TValue>
	{
		private readonly Func<TKey, TValue> initialzier_;
		public HashMap(Func<TKey, TValue> initialzier)
			: base()
		{
			initialzier_ = initialzier;
		}

		public HashMap(Func<TKey, TValue> initialzier, int capacity)
			: base(capacity)
		{
			initialzier_ = initialzier;
		}

		new public TValue this[TKey key]
		{
			get
			{
				if (ContainsKey(key) == false) {
					base[key] = initialzier_(key);
				}

				return base[key];
			}

			set { base[key] = value; }
		}
	}

	public static class Helper
	{
		public static void UpdateMin<T>(ref T target, T value) where T : IComparable<T>
			=> target = target.CompareTo(value) > 0 ? value : target;

		public static void UpdateMin<T>(ref T target, T value, Action<T> onUpdated) where T : IComparable<T>
		{
			if (target.CompareTo(value) > 0) {
				target = value;
				onUpdated(value);
			}
		}

		public static void UpdateMax<T>(ref T target, T value) where T : IComparable<T>
			=> target = target.CompareTo(value) < 0 ? value : target;
		public static void UpdateMax<T>(ref T target, T value, Action<T> onUpdated) where T : IComparable<T>
		{
			if (target.CompareTo(value) < 0) {
				target = value;
				onUpdated(value);
			}
		}

		public static T[] Array<T>(int n, Func<int, T> init)
			=> Enumerable.Range(0, n).Select(x => init(x)).ToArray();
		public static List<T> List<T>(int n, Func<int, T> init)
			=> Enumerable.Range(0, n).Select(x => init(x)).ToList();
		public static T[,] Array2<T>(int n, int m, T init)
		{
			var array = new T[n, m];
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < m; j++) {
					array[i, j] = init;
				}
			}

			return array;
		}

		public static T[,] Array2<T>(int n, int m, Func<int, int, T> initializer)
		{
			var array = new T[n, m];
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < m; j++) {
					array[i, j] = initializer(i, j);
				}
			}

			return array;
		}

		public static T[,,] Array3<T>(int n1, int n2, int n3, T init)
		{
			var array = new T[n1, n2, n3];
			for (int i1 = 0; i1 < n1; i1++) {
				for (int i2 = 0; i2 < n2; i2++) {
					for (int i3 = 0; i3 < n3; i3++) {
						array[i1, i2, i3] = init;
					}
				}
			}

			return array;
		}

		private static readonly int[] delta4_ = { 1, 0, -1, 0, 1 };
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static void DoAt4(int i, int j, int imax, int jmax, Action<int, int> action)
		{
			for (int dn = 0; dn < 4; dn++) {
				int d4i = i + delta4_[dn];
				int d4j = j + delta4_[dn + 1];
				if ((uint)d4i < (uint)imax && (uint)d4j < (uint)jmax) {
					action(d4i, d4j);
				}
			}
		}
	}

	public class Scanner
	{
		private readonly char[] delimiter_ = new char[] { ' ' };
		private readonly string filePath_;
		private readonly Func<string> reader_;
		private string[] buf_;
		private int index_;

		public Scanner(string file = "")
		{
			if (string.IsNullOrWhiteSpace(file)) {
				reader_ = Console.ReadLine;
			} else {
				filePath_ = file;
				var fs = new StreamReader(file);
				reader_ = fs.ReadLine;
			}
			buf_ = new string[0];
			index_ = 0;
		}

		public string NextLine() => reader_();
		public string Next()
		{
			if (index_ < buf_.Length) {
				return buf_[index_++];
			}

			string st = reader_();
			while (st == "") {
				st = reader_();
			}

			buf_ = st.Split(delimiter_, StringSplitOptions.RemoveEmptyEntries);
			if (buf_.Length == 0) {
				return Next();
			}

			index_ = 0;
			return buf_[index_++];
		}

		public int Int() => int.Parse(Next());
		public long Long() => long.Parse(Next());
		public double Double() => double.Parse(Next());

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Int() + add;
			}
			return Array;
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Long() + add;
			}
			return Array;
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Double() + add;
			}
			return Array;
		}

		public void Save(string text)
		{
			if (string.IsNullOrWhiteSpace(filePath_)) {
				return;
			}

			File.WriteAllText(filePath_ + "_output.txt", text);
		}
	}
}

Measured memory_bytes: 49336