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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            string[] strA = Console.ReadLine().Split(' ');
            int[] A = new int[strA.Length];
            double m = 0;
            for (int i = 0; i < strA.Length; i++)
            {
                A[i] = int.Parse(strA[i]);
            }
            Array.Sort(A);
            if (N % 2 == 0)
            {
                m = (double)(A[N / 2 - 1] + A[N / 2]) / 2;
            }
            else
            {
                m = A[N / 2];
            }
            Console.WriteLine(m);
        }      
    }
}