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

namespace Yuki
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            var li = ConvertStringArrayToIntList(Console.ReadLine().Split());
            double ans = 0;

            li.Sort();

            if (N % 2 == 0)
            {
                ans = (li[N / 2 - 1] + li[N / 2]) / 2d;
            }else
            {
                ans = li[N / 2];
            } 

            Console.WriteLine(ans);
        }

        static List<int> ConvertStringArrayToIntList(string[] str)
        {
            var list = new List<int>();
            foreach (var c in str) list.Add(int.Parse(c));
            return list;
        }
    }
}