https://www.acmicpc.net/problem/16486
import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner s=new Scanner(System.in);
int d1=s.nextInt();
int d2=s.nextInt();
double pi=3.141592;
System.out.format("%f",2*d1+2*pi*d2);
}
}