水一下

#include<bits/stdc++.h>
using namespace std;
int main(){
double r,pl = 3.14159;
scanf("%lf",&r);
printf("%.4lf",r * 2);
cout << " ";
printf("%.4lf",r * 2 * pl);
cout << " ";
printf("%.4lf",r * r * pl);
return 0;
}