input: 
  
  def correct_bracketing(brackets: str):
      """ brackets is a string of "<" and ">".
      return True if every opening bracket has a corresponding closing bracket.
  
      >>> correct_bracketing("<")
      False
      >>> correct_bracketing("<>")
      True
      >>> correct_bracketing("<<><>>")
      True
      >>> correct_bracketing("><<>")
      False
      """
  
output:     stack = []
      for bracket in brackets:
          if bracket == "<":
              stack.append(bracket)
          elif bracket == ">":
              if not stack or stack.pop() != "<":
                  return False
      return len(stack) == 0