#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int n;
  cin >> n;
  double x = 0;
  for (int i = 0; i < n; ++i) {
    int tmp;
    cin >> tmp;
    x += (double)tmp;
  }
  x /= n;
  cout << fixed << setprecision(6) << x << '\n';
  return 0;
}
