#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n];
  double c = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    c = c + a[i];
  }
  cout << fixed << setprecision(12) << c / n;
  return 0;
}
