using System;
using System.Linq;

public class Program
{
    public static void Main()
    {
        _ = Console.ReadLine();
        var lst = Console.ReadLine().Split(' ').
                        Select(s => int.Parse(s)).ToList();
        var ct = lst.Count;

        lst.Sort();

        if (ct % 2 == 0)
            Console.Write("{0}", ((lst[ct / 2 -1] + lst[ct / 2])/2.0).ToString());
        else
            Console.Write("{0}", lst[ct / 2].ToString());

        return;
    }
}