import java.util.Scanner;

public class AcmTimusRu {
    public static void main(String argv[]) {
        String[] nf = new String[0];

        Scanner s = new Scanner(System.in);

        double somme = 0;
        double n = s.nextLong();

        for (int i = 0; i < n; i++) {
            somme += s.nextLong();
        }

        System.out.print((somme / n));
    }

}