别看我的

#include <bits/stdc++.h>
using namespace std;

int main()
{
    double r,pi = 3.14159;
    cin >> r;
    printf("%.4lf", r*2);
    cout << " ";
    printf("%.4lf", r*2*pi);
    cout << " ";
    printf("%.4lf", r*r*pi);
    return 0;
}