Double r,s;
double p;
p=3.141592653589793238462643383;
Scanner input=new Scanner(System.in);
r=input.nextDouble();
s=p*r*r;
System.out.println(s);
double p;
p=3.141592653589793238462643383;
Scanner input=new Scanner(System.in);
r=input.nextDouble();
s=p*r*r;
System.out.println(s);