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