git-test/YUAN(2).cpp

#include<iostream>
using namespace std;

int main()
{  
    const double pi=3.14;
    double r,c,s;
    cin>>r;
    c=2.0*pi*r ;
    s=pi*r*r;
    cout<<c<<endl;
    cout<<s<<endl;
    

    return 0 ;
}