input: from typing import List, Optional
  
  
  def vowelCheck(inputString: str) -> Optional[str]:
      """ Check if a given string contains any vowel and return the first found vowel.
      >>> vowelCheck('Hello World')
      'e'
      >>> vowelCheck('Python')
      'o'
      """
      vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']
      for x in inputString:
          if x in vowels:
              return x
output:     return None