#include <bits/stdc++.h>
using namespace std;
void fast() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
}
int main() {
  fast();
  double n;
  cin >> n;
  vector<double> v(n);
  for (int i = 0; i < n; i++) cin >> v[i];
  double sum = 0;
  for (int i = 0; i < n; i++) sum += v[i] / 100.0;
  double res = (sum / n) * 100.0;
  cout << fixed << setprecision(12) << res << endl;
  cin.ignore();
  cin.get();
  return 0;
}
