using System;

public class Program {
	public static void Main(string[] args) {
		int len = int.Parse(Console.ReadLine());
		string[] s = Console.ReadLine().Split(' ');
		Array.Sort(s);
		if (len % 2 == 0) {
			float mid = (float.Parse(s[len/2-1]) + float.Parse(s[len/2])) / 2;
			Console.WriteLine(mid);
		} else {
			Console.WriteLine(s[len/2]);
		}
	}
}