#include <stdio.h>

#define PI 3.14159265358979323846 

double delta_cone(double r, double h) {
    return (1.0 / 3.0) * PI * r * r * h; 
}

int main() {
    double radius, height;

    printf("r");
    scanf("%lf", &radius);
    printf("h");
    scanf("%lf", &height);

    double volume = delta_cone(radius, height);

    printf("円錐の体積: %.2f\n", volume);

	return 0;
}