#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  int n;
  cin >> n;
  double x = 0, result;
  for (int i = 0; i < n; i++) {
    double p;
    cin >> p;
    x += p;
  }
  result = x / n;
  cout << result << endl;
  return 0;
}
