#include <stdio.h>
#include <math.h>

int main() {
    int r, h;

    if (scanf("%d", &r) != 1 || scanf("%d", &h) != 1) {
        printf("Invalid input\n");
        return 0;
    }

    if (r < 0 || h < 0) {
        printf("Invalid input\n");
        return 0;
    }

    double surfaceArea = 2 * M_PI * r * h + 2 * M_PI * r * r;

    printf("%.2f\n", surfaceArea);

    return 0;
}