using System;
public class Program
{
    public static void Main()
    {
        int num = int.Parse(Console.ReadLine() ?? string.Empty);
        string[] number = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');

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

        for (int i = 0;i < numnum.Length-1; i++)
        {
            for (int j = 0; j < numnum.Length - 1; j++)
            {
                if (numnum[j] > numnum[j + 1])
                {
                    int box = numnum[j];

                    numnum[j] = numnum[j + 1];
                    numnum[j + 1] = box;
                }
            }
        }

        if(num ==1)
        {
            Console.WriteLine(number[0]);
        }
        else if(num % 2 != 0)
        {
            int aa = num/2;
            Console.WriteLine("{0}", numnum[aa]);
        }
        else
        {
            double ans = numnum[num / 2] + numnum[(num / 2) - 1];
            ans /= 2;
            Console.WriteLine("{0}", ans);
        }

    }
}