input: def validate_bracket_sequence(brackets: str):
      """ 
      brackets is a string containing "<" and ">" symbols.
      return True if each "<" has a matching ">" in the string.
  
      >>> validate_bracket_sequence("<")
      False
      >>> validate_bracket_sequence("<>")
      True
      >>> validate_bracket_sequence("<<><>>")
      True
      >>> validate_bracket_sequence("><<>")
      False
      """
output:     
      count = 0
      for bracket in brackets:
          if bracket == '<':
              count += 1
          elif bracket == '>':
              count -= 1
          if count < 0:
              return False
      return count == 0
  