using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Magatro
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        int[] a = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
        Array.Sort(a);
        if (N % 2 == 0)
        {
            Console.WriteLine((double)(a[N / 2] + a[N / 2 - 1]) / 2);
        }
        else
        {
            Console.WriteLine(a[N / 2]);
        }
    }
}