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

class Program
{
    static void Main()
    {
        int N = int.Parse(ReadLine());
        var a = ReadLine().Split().Select(int.Parse).ToList();
        a.Sort();
        WriteLine(N % 2 == 0 ? (double)(a[N / 2 - 1] + a[N / 2]) / 2 : a[N / 2]);
    }
}