#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n;
  double sum = 0;
  cin >> n;
  double a[n];
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (long long int i = 0; i < n; i++) {
    sum += a[i];
  }
  double avg = sum / n;
  cout << setprecision(13) << avg << endl;
  return 0;
}
