input: def vowelCheck(inputString: str) -> str:
      """ Detect a vowel in the given string.
      >>> 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 ''