#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: huanglingkai
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/