#include <iostream> #include<iomanip> using namespace std; int main() { double a; cin >> a; double b = 3.14159; cout << fixed << setprecision(4) << 2 * a << " " << fixed << setprecision(4) << 2 * b * a << " " << fixed << setprecision(4) << b * (a * a); return 0; } //泪目,第一次提交,没考虑精度