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 a = Array.ConvertAll(line, int.Parse);
        getAns(n, a);
    }
    static void getAns(int n, int[] a)
    {
        var pL = 0;
        var pr = 2 * n - 1;
        var h = 0L;
        var t = 0L;
        while (pr - pL > 1)
        {
            if (a[pL] - a[pL + 1] >= a[pr] - a[pr - 1])
            {
                h += a[pL];
                t += a[pL + 1];
                pL += 2;
            }
            else
            {
                h += a[pr];
                t += a[pr - 1];
                pr -= 2;
            }
        }
        h += Max(a[pL], a[pr]);
        t += Min(a[pL], a[pr]);
        Console.WriteLine(h - t);
    }
}