import java.util.*;

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

        sc.close();

    }
}