//http://uva.onlinejudge.org/external/116/11636.html
// 11636 Hello World!
#include
#include
using namespace std;

while (1)
{
cin >> N;
if (N <0)
break;
k = ceil(log(N)/log(2));
int i=0;
mycase ++;
cout <<"Case " << mycase << ": " << k << endl;
}
return 0;
}