#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  double a = 0;
  for (int i = 0; i < (n); i++) {
    double c;
    cin >> c;
    a += c;
  }
  cout << fixed << setprecision(10);
  cout << a / n << endl;
  return 0;
}
