#include <bits/stdc++.h>
using namespace std;
double x, n, a[107];
int main() {
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    x += (a[i] / 100);
  }
  double tmp = x / n;
  tmp *= 100;
  cout << fixed;
  cout << setprecision(12) << tmp;
}
