text: #include <iostream>  // std::cout, std::cin
  using namespace std;
  int main()
  {
      int n;
      cin >> n;
  
      double volume_of_constituent = 0;
      int volume_of_all_constituents = n;
  
      while(n--){
          double p;
          cin >> p;
          volume_of_constituent += p;
      }
  
      double volume_fraction = volume_of_constituent/volume_of_all_constituents;
      cout << volume_fraction << endl;
      return 0;
  }
  