#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, arr[101];
  cin >> n;
  double a = 0.0, sum = 0.0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  a = sum / n;
  cout << fixed << setprecision(12) << a << endl;
  return 0;
}
