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