#include<stdio.h>
#define pi 3.1415926
int main()
{
	int n;
	double s;
	scanf("%d",&n);
	while(n--)
	{
		double m;
		scanf("%lf",&m);
		s=(m*m*pi)/3;
		printf("%.2lf\n",s);
	}
	return 0;
}