using static System.Math;
using System;

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        string[] line = Console.ReadLine().Trim().Split(' ');
        var p = Array.ConvertAll(line, int.Parse);
        getAns(n, p);
    }
    static void getAns(int n, int[] p)
    {
        if (n == 1) { Console.WriteLine(0); return; }
        var a = new int[n + 1];
        for (int i = 0; i < n; i++) a[p[i]] = i + 1;
        long t = a[1] - a[2];
        var ans = t;
        for (int i = 3; i <= n; i++)
        {
            t += 2L * a[i - 1] - a[i];
            ans = Max(ans, t);
        }
        Console.WriteLine(Max(0, ans));
    }
}