using System;

class Program
{
    static void Main(string[] args)
    {
        string line = System.Console.ReadLine().Trim();
        int N = int.Parse(line);
        
        line = System.Console.ReadLine().Trim();
        string[] Data = line.Split(' ');

        int[] num = new int[N];
        for (int i = 0; i < N; i++)
        {
            num[i] = int.Parse(Data[i]);
        }

        Array.Sort(num);

        if(N %2 ==0)
        {
            double x = (double)((num[N / 2]+ num[N / 2 - 1])) / 2;
            System.Console.WriteLine(x);
            return;
        }
        else
        {
            System.Console.WriteLine(num[N/2]);
            return;
        }     
    }
}