#include <iostream>
#include <cstring>
#include <stdio.h>
#include <string.h>
#include <time.h>

class Circle{
  private:
  double member_radius;
 public:
 Circle(){}
 Circle(double member_radius)
 {
     this->member_radius=member_radius;
 }
 double getMemberRadius()
 {
     return member_radius;
 }
 void setRadius(double radius)
 {
     member_radius=radius;
 }

  ~Circle(){}
  double parametar()
  {
     double r = member_radius;
     double p = r * 3.14;
      return 2*p;
  }
};
  void info(Circle crc)
    {
       std::cout<<"Parametar and area"<< crc.parametar() <<std::endl;
    }

int main() {

      int n;
    std::cout<<"Vnesi broj na krugovi"<<std::endl;
    std::cin >> n;
     Circle crc[n];
 for (int i=0; i<n; i++) {
       double radius;

          std::cin >> radius;
           crc[i]= Circle(radius);
    }

   //crc.parametar();

    for(int i=0;i<n;i++)
    {
       info(crc[i]);
    }


    return 0;
}