1095

 1 #include <iostream>

 2 #include <iomanip>

 3 using namespace std;

 4 #define p 3.1415

 5 int main()

 6 {

 7     int n;

 8     double s,r;

 9     cin>>n;

10     while(n--)

11     {

12         cin>>r;

13         s=p*r*r;

14     cout<<setiosflags(ios::fixed)<<setprecision(6)<<s<<endl;

15     }

16     return 0;

17 }