#include <iostream>
using namespace std;
class statistics{
    double mean;
    
public:
      statistics(int arr[],int n){
          double sum =0;
          for (int i=0;i<n;i++){
              sum+=arr[i]
          }
          mean =sum/n;
      }
      statistics(const statistics& obj){
          mean = obj.mean;
      }
      void display(){
          cout<< mean;
      }
     
};
int main(){
    int n;
    cin>> n;
    if(n<0){
        cout<<"Invalid input";
        return 0;
    }
    int arr[n];
    for (int i=0 ; i<n; i++){
        cin>> arr[i]
    }
     statistics s1(arr,n);
     statistics s2=s1;
     s2.display();
     return 0;
}