#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x, i;
  double s = 0;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> x;
    s = s + x;
  }
  s = s / n;
  cout << s << endl;
  return 0;
}
