using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using static System.Console;
using static System.Convert;
using static System.Math;
using static Extentions;

class IO
{
    int idx;
    string[] input;

    public IO(TextReader reader)
    {
        input = reader.ReadToEnd().Split(new[] { " ", Environment.NewLine },
            StringSplitOptions.RemoveEmptyEntries);
    }

    T Get<T>(Func<string, T> parser) => parser(input[idx++]);

    public string S => Get(s => s);
    public char C => Get(char.Parse);
    public int I => Get(int.Parse);
    public long L => Get(long.Parse);
    public double F => Get(double.Parse);
    public decimal D => Get(decimal.Parse);
    public BigInteger B => Get(BigInteger.Parse);

    T[] Gets<T>(int n, Func<string, T> parser)
        => input.Skip((idx += n) - n).Take(n).Select(parser).ToArray();

    public string[] Ss(int n) => Gets(n, s => s);
    public char[] Cs(int n) => Gets(n, char.Parse);
    public int[] Is(int n) => Gets(n, int.Parse);
    public long[] Ls(int n) => Gets(n, long.Parse);
    public double[] Fs(int n) => Gets(n, double.Parse);
    public decimal[] Ds(int n) => Gets(n, decimal.Parse);
    public BigInteger[] Bs(int n) => Gets(n, BigInteger.Parse);

    public void Write<T>(params T[] xs) => WriteLine(string.Join(" ", xs));
    public void Write(params object[] xs) => WriteLine(string.Join(" ", xs));
}

#region ref. http://qiita.com/Camypaper/items/de6d576fe5513743a50e
class PriorityQueue<T>
{
    private readonly List<T> heap;
    private readonly Comparison<T> compare;
    private int size;
    public PriorityQueue() : this(Comparer<T>.Default) { }
    public PriorityQueue(IComparer<T> comparer) : this(16, comparer.Compare) { }
    public PriorityQueue(Comparison<T> comparison) : this(16, comparison) { }
    public PriorityQueue(int capacity, Comparison<T> comparison)
    {
        this.heap = new List<T>(capacity);
        this.compare = comparison;
    }
    public void Enqueue(T item)
    {
        this.heap.Add(item);
        var i = size++;
        while (i > 0)
        {
            var p = (i - 1) >> 1;
            if (compare(this.heap[p], item) <= 0)
                break;
            this.heap[i] = heap[p];
            i = p;
        }
        this.heap[i] = item;

    }
    public T Dequeue()
    {
        var ret = this.heap[0];
        var x = this.heap[--size];
        var i = 0;
        while ((i << 1) + 1 < size)
        {
            var a = (i << 1) + 1;
            var b = (i << 1) + 2;
            if (b < size && compare(heap[b], heap[a]) < 0) a = b;
            if (compare(heap[a], x) >= 0)
                break;
            heap[i] = heap[a];
            i = a;
        }
        heap[i] = x;
        heap.RemoveAt(size);
        return ret;
    }
    public T Peek() { return heap[0]; }
    public int Count { get { return size; } }
    public bool Any() { return size > 0; }
}
#endregion

static class Extentions
{
    public static void ForEach<T>(this IEnumerable<T> seq, Action<T> act)
    {
        foreach (var item in seq) act(item);
    }
}

static class Program
{
    public static void Main()
    {
#if !DEBUG
        SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
#endif
        Solve(new IO(In));
        Out.Flush();
    }

    static void Solve(IO io)
    {
        var n = io.I;
        var a = io.Is(n);
        var b = io.Is(n);

        var ans = int.MaxValue;

        for (var i = 0; i < n; i++)
        {
            var pq = new PriorityQueue<long>();
            a.Select(x => Encode(x, 0)).ForEach(pq.Enqueue);

            for (var j = 0; j < n; j++)
            {
                var ta = Decode(pq.Dequeue());
                var tb = b[j < n - i ? j + i : j - (n - i)];
                pq.Enqueue(Encode(ta.Item1 + tb / 2, ta.Item2 + 1));
            }

            var t = 0;
            while (pq.Any()) t = Max(t, Decode(pq.Dequeue()).Item2);
            ans = Min(ans, t);
        }

        io.Write(ans);
    }

    static long Encode(int level, int times) => level * 10000 + times;

    static Tuple<int, int> Decode(long encoded)
        => Tuple.Create((int)(encoded / 10000), (int)(encoded % 10000));
}