#include <iostream>
#include <iomanip>

const double PI = 3.1415926;

int main() {
    double r, h;
    std::cin >> r >> h;
    double circle_area = PI * r * r;
    double circle_circumference = PI * 2 * r;
    double surface_area = 2 * circle_area + circle_circumference * h;
    std::cout << std::fixed << std::setprecision(2) << surface_area << std::endl;
    return 0;
}    
/**************************************************************
	Problem: 1623
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/