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

public class Program
{
    public void Proc(){
        Reader.IsDebug =  false;
        
        int numCOunt = int.Parse(Reader.ReadLine());
        
        List<int> numList = new List<int>();
        numList.AddRange(Reader.GetInt());
        numList.Sort();
        double ans = numList[0];
        if(numList.Count % 2 == 0 && numList.Count >= 2) {
            int idx1 = numList.Count / 2;
            ans = (numList[idx1 - 1] + numList[idx1]) / 2.0;
        } else
        {
             int idx = numList.Count / 2;
             ans = numList[idx];
        }
        Console.WriteLine(ans.ToString("#################0.0"));

    }

    public static void Main(string[] args)
    {
        Program prg = new Program();
        prg.Proc();
    }
}

class Reader
{
    public static bool IsDebug = true;
    
    private static System.IO.StringReader sr;
    
    public static string ReadLine() {
        if(IsDebug) {
            if(sr == null) {
                sr = new System.IO.StringReader(initStr.Trim());
            }
            return sr.ReadLine();
        } else {
            return Console.ReadLine();
        }
    }
    
    public static int[] GetInt(char delimiter = ' ') {
        string[] inpt = ReadLine().Split(delimiter);
        int[] ret = new int[inpt.Length];
        for(int i=0; i<inpt.Length; i++) {
            ret[i] = int.Parse(inpt[i]);
        }
        return ret;
    }
    
    private static string initStr = @"


6
1 2 3 4 5 6

    ";
}