import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.next());
        ArrayList<Integer> list = new ArrayList<>();

        for (int i = 0; i < n; i++) {
            list.add(Integer.parseInt(scanner.next()));
        }

        Collections.sort(list);

        float answer;
        if (n % 2 == 0) {
            answer = ((list.get((int) (n / 2.f) - 1)) + (list.get((int) (n / 2.f)))) / 2.f;
        } else {
            answer = ((float) list.get((n / 2)));
        }

        System.out.println(answer);
    }
}