#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, p;
  double sum = 0.0;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> p;
    sum += p;
  }
  sum = sum / n;
  cout << fixed << setprecision(12) << sum << endl;
  return 0;
}
