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

namespace No275
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			var n = Convert.ToInt32(Console.ReadLine ());
			string[] line = Console.ReadLine ().Split(' ');
			int[] data = line.Select (s => Convert.ToInt32 (s)).ToArray();
			Array.Sort (data);
			if (data.Length % 2 == 1) {
				Console.WriteLine (data [data.Length / 2].ToString ());
				return;
			}
			var a = data [data.Length / 2];
			var b = data [data.Length / 2-1];
			var mid = ((double)a + (double)b) / 2d;
			Console.WriteLine (mid.ToString ());
		}
	}
}