import java.io.ObjectInputStream.GetField;
import java.net.NetworkInterface;
import java.util.*;
import java.util.zip.Inflater;

import javax.swing.plaf.synth.SynthSpinnerUI;


public class Main {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		int[] input = new int[N];
		for(int i=0; i<N; i++) input[i]=sc.nextInt();
		Arrays.sort(input);
		
		if(N%2!=0){
			System.out.println(input[(N-1)/2]);
		}else{
			System.out.println(1.0*(input[N/2]+input[(N-1)/2])/2);
		}
	}	
}