#include<bits/stdc++.h>
using namespace std;
int main()
{
    int r,h;
    float pi=3.1415926,c,s,a;
    cin>>r>>h;
	s=pi*r*r;
    c=pi*r*2;
    a=s*2+c*h;
    printf("%.2f",a);
    return 0;
}
/**************************************************************
	Problem: 1623
	User: fuhoubin
	Language: C++
	Result: Wrong Answer
****************************************************************/