import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int count = scanner.nextInt();

        float[] numbers = new float[count];

        float sum = 0;
        int iterator = 0;

        if (count > 0) {
            while (iterator < count) {
                numbers[iterator] = Float.parseFloat(scanner.next());
                sum += numbers[iterator];
                iterator++;
            }
            System.out.printf("%.2f", sum / count);
        } else {
            System.out.print("0.00");
        }

    }
}