#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, p[100];
  cin >> n;
  double sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> p[i];
    sum += p[i];
  }
  cout << fixed;
  cout << setprecision(12);
  cout << sum / n;
  return 0;
}
