1 #include<stdio.h>
 2 #define PI 3.1415926
 3 int main()
 4 {
 5     int n;
 6     scanf("%d",&n);
 7     while(n--)
 8     {
 9         double m;
10         scanf("%lf",&m);
11         printf("%.2lf\n",PI*m*m/3.0);
12     }
13 }