#include <iostream>
using namespace std;

class statistics {
    double mean;
    
    public:
    statistics(int arr[], int n){
        int sum = 0;
        for(int i = 0; i < n; i++){
            sum +=arr[i];
        }
        mean = (double)sum / n;
        
    }
    statistics(const statistics &s){
        mean = s.mean;
    }
    void diaplay (){
        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;
}