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