import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		int ans = 0;
		for(int i = 0 ; i < n ; i++) {
			a[i] = sc.nextInt();
		}
		Arrays.sort(a);
		int center = (n - 1) / 2;
		if(a.length % 2 == 0) {
			System.out.println((a[center] + a[center + 1]) / 2.0);
		} else {
			System.out.println(a[center]);
		}

 	}
}