#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  int n, k;
  cin >> n;
  int sum = 0;
  for (int i = (1), _b = (n); i <= _b; i++) {
    cin >> k;
    sum += k;
  }
  sum *= 100;
  double res = sum * 1.0 / (n * 100);
  cout << fixed << setprecision(9) << res;
  return 0;
}
