Problem Statement 
 You have k objects divided evenly into num
piles. Unfortunately, some of the digits of k may have been erased
(replaced with 'X's in the input).
Return the number of possible values that k could have been.


Definition 
 Class:  DigitFiller  Method:  howMany  Parameters:  String, int  Returns:  long  Method signature:  long howMany(String k, int num)  (be sure your method is public) 




Constraints 
  k will contain between 2 and 18 characters inclusive. 
  Each character in k will be a digit ('0''9') or 'X'. 
  Character 0 of k will be a positive digit ('1''9'). 
  num will be between 1 and 10000 inclusive. 
  The return value will be at least 1. 

Examples 
0)  
  Returns: 1  Since the objects are divided evenly into 9 piles, 81 is the only possible solution. 


1)  
  Returns: 10  Here there are 10 possible values k could have been. 


2)  
  Returns: 1  None of the digits are missing. 


3)  
 
4)  
 