#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  scanf("%d", &n);
  double p[1 << 7];
  double sum = 0;
  for (int i = 0; i < n; i++) {
    scanf("%lf", &p[i]);
    sum += p[i];
  }
  printf("%.5lf\n", sum / n);
  return 0;
}
