lightoj1022

CODE

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <iomanip>
#include <cmath>
#define CL(a,b) memset(a,b,sizeof(a))
using namespace std;

const double pi = acos(-1);
int n,k,nCase;
double r;
int main()
{
        int t;
        cin >>t;
        while(t--)
        {
                cin >> r;
                cout << "Case "<<++nCase<<": ";
                cout << fixed<<setprecision(2)<<r*r*4-pi*r*r<<endl;
        }

        return 0;
}