using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        WriteLine(Heck(n, a));
    }
    static long Heck(int n, int[] a)
    {
        if (n == 1)
        {
            return 0;
        }
        var pos = new int[n];
        for (var i = 0; i < n; ++i) pos[a[i] - 1] = i;
        var tmp = 0L;
        var ans = tmp;
        for (var i = 1; i < n; ++i)
        {
            if (i == 1) tmp = pos[i - 1] - pos[i];
            else tmp += pos[i - 1] * 2 - pos[i] + 1;
            ans = Math.Max(ans, tmp);
        }
        return ans;
    }
}