import java.util.Scanner;

public class ArrayAverage {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long sum = 0;
        for (int i = 0; i < n; i++) {
            sum += sc.nextInt();
        }
        double avg = (double) sum / n;
        System.out.printf("%.2f%n", avg);
        sc.close();
    }
}