#include<bits/stdc++.h>
using namespace std;
double r,h,s1,s2;
const double PI=3.1415926;
int main(){
	cin>>r>>h;
	s1=PI*r*r*2.0;
	s2=PI*r*2.0*h;
	cout<<fixed<<setprecision(2)<<s1+s2;
	return 0;
}
/**************************************************************
	Problem: 1623
	User: zhangziang
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/