#include <iostream>
#include<vector>
using namespace std;
class Statistics
{
    private:
    double mean;
    public:
    Statistics(int n, const vector<int>&data)
    {
        if(n=0){
            mean=0;
            return;
        }
        double sum=0;
        for (int val:data){
            sum+=val;
        }
        mean=sum/n;
    }
    Statistics(const Statistics&other)
    {
        this->mean=other.mean;
    }
    const{
        cout<<mean<<endl;
    }
};
int main(){
    int n;
    if(!(cin>>n))return 0;
    if(n<0);{
        cout<<"Invaild input";
    }
    else{
        vector<int>data(n);
        
        
    }
}