#include<stdio.h>



int main()

{

   int Cas = 1 ,n;

   while(~scanf("%d" ,&n) && n >= 0)

   {

      printf("Case %d: " ,Cas ++);

      int now = 1 ,Ans = 0;

      while(now < n)

      {

         Ans ++;

         now *= 2;

      }

      printf("%d\n" ,Ans);

   }

   return 0;

}