using System;
using System.Linq;

namespace No._275
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.ReadLine();
            var num = Console.ReadLine().Split(' ').Select(int.Parse).OrderBy(_ => _).ToList();
            double m = 0;

            if (num.Count % 2 != 0)
            {
                m = num.ElementAt(num.Count / 2);
            }
            else
            {
                m = num.Skip(num.Count / 2 -1).Take(2).Average();
            }

            Console.WriteLine(m);
        }
    }
}