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

class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = scan.nextInt();
        }
        Arrays.sort(a);
        int j = n / 2;
        if (n % 2 != 0) {
            System.out.println(a[j]);
        } else {
            System.out.println((double)(a[j - 1] + a[j]) / 2);
        }
        scan.close();
    }
}