cta

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

int main()
{
    int v;
    double s, r, angle, area;

    scanf(" %d %lf", &v, &s);

    if(v>=3 && v<=359 && s>=1 && s<=1E9){
        angle = 3.14159265358979323846264338/v;
        r = s/(2*sin(angle));
        area = 3.14159265358979323846264338 * r * r;
        printf("%.9lf", area);
    }
    return 0;
}