import java.util.Scanner;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		List<Integer> list = new ArrayList<Integer>();
		
		for(int i = 0 ; i < num ; i++)list.add(sc.nextInt());
		
		Collections.sort(list);
		
		if(num % 2 == 0) {
			System.out.println((float)(list.get(num / 2 ) + (list.get(num / 2 - 1) )) / 2);
		}else {
			System.out.println(list.get(num / 2 ));
		}
	}
}