#include <iostream>
using namespace std;
class statistics{
    private:
    int n;
    double mean;
    
    public:
    statistics(int size , int arr[]){
        n = size;
        if (n<=0){
            mean=0;
            return;
        }
        int sum = 0;
        for(int i = 0 ; i< n;i++){
            sum+=arr[i];
        }
        mean = (double)sum/n;
    }
        statistics(const statistics &s){
            n = s.n;
            
        }
        double getmeam()const{
            return mean;
            
        }
    
};
int main(){
    int n;
    cin>>n;
    if(n<0){
        cout<<"Invalid input";
        return 0;
    }
    int arr[10];
    for(int i = 0; i < n ; i++){
        cin>>arr[i];
    }
    statistics s1(n,arr);
    statistics s2(s1);
    
    if (n==0){
        cout<<0;
        }
    else{
        cout<<s2.getmean();
    }
    return
}