#include <stdio.h>

int main(void) {
  int n;
  scanf("%i", &n);
  double arr[n];
  for (int i = 0; i < n; i++) {
    scanf("%lf", &arr[i]);
  }
  double sum = 0;
  for (int i = 0; i < n; i++) {
    sum += arr[i];
  }
  printf("%.2lf\n", sum / n);
}