#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  double sum = 0;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  for (int j = 0; j < n; j++) {
    sum += arr[j];
  }
  cout << sum / n;
  return 0;
}
