code: 
  
  
  import random
  import sys
  
  __snake_case             =	'''ABCDEFGHIJKLMNOPQRSTUVWXYZ'''
  
  
  
  
  
  
  def 		_A		(		)				->   None:
  
  
       """simple docstring"""
  
  
       __UpperCamelCase   = input('Enter message: '   )
       __UpperCamelCase   = 'LFWOAYUISVKMNXPBDCRJTQEGHZ'
       __UpperCamelCase   = input('Encrypt/Decrypt [e/d]: '   )
  
       check_valid_key(_lowercase   )
  
       if resp.lower().startswith('e'   ):
            __UpperCamelCase   = 'encrypt'
            __UpperCamelCase   = encrypt_message(_lowercase				,     _lowercase   )
       elif resp.lower().startswith('d'   ):
            __UpperCamelCase   = 'decrypt'
            __UpperCamelCase   = decrypt_message(_lowercase				,     _lowercase   )
  
       print(f'''\n{mode.title()}ion: \n{translated}'''   )
  
  
  
  
  
  
  def 		_A		(		_lowercase   )				->   None:
  
  
       """simple docstring"""
  
  
       __UpperCamelCase   = list(_lowercase   )
       __UpperCamelCase   = list(_lowercase   )
       key_list.sort()
       letters_list.sort()
  
       if key_list != letters_list:
            sys.exit('Error in the key or symbol set.'   )
  
  
  
  
  
  
  def 		_A		(		_lowercase				,     _lowercase   )				->   str:
  
  
       """simple docstring"""
  
  
       return translate_message(_lowercase				,     _lowercase				,     'encrypt'   )
  
  
  
  
  
  
  def 		_A		(		_lowercase				,     _lowercase   )				->   str:
  
  
       """simple docstring"""
  
  
       return translate_message(_lowercase				,     _lowercase				,     'decrypt'   )
  
  
  
  
  
  
  def 		_A		(		_lowercase				,     _lowercase				,     _lowercase   )				->   str:
  
  
       """simple docstring"""
  
  
       __UpperCamelCase   = ''
       __UpperCamelCase   = LETTERS
       __UpperCamelCase   = key
  
       if mode == "decrypt":
            __UpperCamelCase,						__UpperCamelCase   = chars_b, chars_a
  
       for symbol in message:
            if symbol.upper() in chars_a:
                 __UpperCamelCase   = chars_a.find(symbol.upper()   )
                 if symbol.isupper():
                      translated += chars_b[sym_index].upper()
                 else:
                      translated += chars_b[sym_index].lower()
            else:
                 translated += symbol
  
       return translated
  
  
  
  
  
  
  def 		_A		(		)				->   str:
  
  
       """simple docstring"""
  
  
       __UpperCamelCase   = list(_lowercase   )
       random.shuffle(_lowercase   )
       return "".join(_lowercase   )
  
  
  if __name__ == "__main__":
      main()
  
  
  
style_context: 
  
  
  def 		_A		(		_lowercase   )				->   bool:
  
  
       """simple docstring"""
  
  
       if not isinstance(_lowercase				,     _lowercase   ):
            raise ValueError('Input series is not valid, valid series - [1, 2/3, 2]'   )
       if len(_lowercase   ) == 0:
            raise ValueError('Input list must be a non empty list'   )
       if len(_lowercase   ) == 1 and series[0] != 0:
            return True
       __UpperCamelCase   = []
       __UpperCamelCase   = len(_lowercase   )
       for i in range(0				,     _lowercase   ):
            if series[i] == 0:
                 raise ValueError('Input series cannot have 0 as an element'   )
            rec_series.append(1 / series[i]   )
       __UpperCamelCase   = rec_series[1] - rec_series[0]
       for index in range(2				,     _lowercase   ):
            if rec_series[index] - rec_series[index - 1] != common_diff:
                 return False
       return True
  
  
  
  
  
  
  def 		_A		(		_lowercase   )				->   float:
  
  
       """simple docstring"""
  
  
       if not isinstance(_lowercase				,     _lowercase   ):
            raise ValueError('Input series is not valid, valid series - [2, 4, 6]'   )
       if len(_lowercase   ) == 0:
            raise ValueError('Input list must be a non empty list'   )
       __UpperCamelCase   = 0
       for val in series:
            answer += 1 / val
       return len(_lowercase   ) / answer
  
  
  if __name__ == "__main__":
      import doctest
  
      doctest.testmod()
  
  
  