#include<bits/stdc++.h>
using namespace std;
int main(){
	double r,h,z,m,b;
	const double PI= 3.1415926;
	cin>>r>>h;
	z=PI*2*r;
	m=PI*r*r;
	b=m*2+z*h;
	printf("%.2f",b);
	return 0;
}
/**************************************************************
	Problem: 1623
	User: xiaojingxuan
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/