input: def special_character_count(text: str) -> int:
      """
      You are given a string text. A character is considered special if it is present in both its lowercase and uppercase forms within the text.
  
      Return the count of special characters in text.
  
      Examples:
      >>> text = "aaAbcBC"
      3
      >>> text = "abc"
      0
      >>> text = "abBCab"
      1
  
      Constraints:
      1 <= text.length <= 50
      text consists of only lowercase and uppercase English letters.
      """
output:     special_characters = set()
      for char in text:
          if char.islower() and char.upper() in text:
              special_characters.add(char.lower())
          elif char.isupper() and char.lower() in text:
              special_characters.add(char.lower())
      return len(special_characters)