import java.util.Arrays;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int a = sc.nextInt();
        double[] b = new double[a];
        for (int i = 0; i < a; i++) {
            b[i] = sc.nextInt();
        }
        Arrays.sort(b);
        if (a % 2 == 1) {
            System.out.println(b[a / 2]);
        } else {
            System.out.println((b[a / 2] + b[a / 2 - 1]) / 2);
        }
    }
}