https://old.ynoip.cn/p/1109

#include <cstdio>
using namespace std;
#define PI 3.1415926

int main(void) {
	double r;
	scanf("%lf", &r);
	printf("%.4lf %.4lf %.4lf", r * 2, 2 * r * PI, r * r * PI);
	return 0;
}