human
Solve in Python:
You are given a license key represented as a string S which consists only alphanumeric character and dashes. The string is separated into N+1 groups by N dashes.

Given a number K, we would want to reformat the strings such that each group contains exactly K characters, except for the first group which could be shorter than K, but still must contain at least one character. Furthermore, there must be a dash inserted between two groups and all lowercase letters should be converted to uppercase.

Given a non-empty string S and a number K, format the string according to the rules described above.

Example 1:

Input: S = "5F3Z-2e-9-w", K = 4

Output: "5F3Z-2E9W"

Explanation: The string S has been split into two parts, each part has 4 characters.
Note that the two extra dashes are not needed and can be removed.



Example 2:

Input: S = "2-5g-3-J", K = 2

Output: "2-5G-3J"

Explanation: The string S has been split into three parts, each part has 2 characters except the first part as it could be shorter as mentioned above.


Note:

The length of string S will not exceed 12,000, and K is a positive integer.
String S consists only of alphanumerical characters (a-z and/or A-Z and/or 0-9) and dashes(-).
String S is non-empty.

What is a the Python program you requested?
assistant
#Here is the Python program you requested.

class Solution:
     def licenseKeyFormatting(self, S, K):
         """
         :type S: str
         :type K: int
         :rtype: str
         """
      
         if(len(S)<=1):
             return S.upper().strip('-')
         S = S.upper()
         n_dash = S.count('-')
         n = len(S)-n_dash
         form_S = ""
         if(n%K == 0):
             begin_at = K-1
         else:
             left = n%K
             begin_at = left-1
         steps = 0 
         abs_ind = 0
         norm_ind = 0
         
         while(abs_ind <=begin_at and norm_ind < len(S)):
             if(S[norm_ind]=='-'):
                 norm_ind +=1
                 continue
             form_S += S[norm_ind]
             abs_ind +=1
             norm_ind +=1
         form_S += '-'
         for char_ind in range(norm_ind, len(S)):
             if(S[char_ind] =="-"):
                 continue
                 
             elif(steps == K-1 and abs_ind > begin_at):
                 form_S += S[char_ind]+'-'
                 steps =0
             else:
                 form_S += S[char_ind]
                 steps += 1
 
             abs_ind += 1
         
     
         return form_S.strip('-')