| ||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.
|Method signature:||long howMany(String k, int num)|
|(be sure your method is public)|
|-||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.|
|Since the objects are divided evenly into 9 piles, 81 is the only possible solution.|
|Here there are 10 possible values k could have been.|
|None of the digits are missing.|