#include<bits/stdc++.h>
using namespace std;
int main(){
	int r,h;
	double pi = 3.1415926;
	cin>>r>>h;
	cout<<fixed<<setprecision(2);
	cout<<2*r*pi*h + r*r*pi*2; 
	return 0;
}


/**************************************************************
	Problem: 1623
	User: admin
	Language: C++
	Result: Accepted
	Time:22 ms
	Memory:2072 kb
****************************************************************/