using System;
using System.Linq;
using System.Collections.Generic;

namespace test20190423
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.ReadLine();
            var ss = Console.ReadLine().Split(new String[] { " " }, StringSplitOptions.RemoveEmptyEntries).Select(x => int.Parse(x)).ToList();
            ss.Sort();
            var n = ss.Count;
            if (n % 2 != 0) Console.WriteLine(ss[n / 2]);
            else Console.WriteLine((ss[n / 2 - 1] + ss[n / 2]) / 2.0);
            Console.ReadLine();
        }
    }
}