#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, a;
  cin >> n;
  double sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> a;
    sum = sum + a / 100;
  }
  sum = sum / n;
  cout << fixed;
  cout << setprecision(6) << sum * 100;
  return 0;
}
