input: 
  def simple_chatbot(user_input: str) -> str:
      """ A simple chatbot with state diagrams to respond to user input. 
      The chatbot initializes at state0 and transitions between states based on user replies.
      >>> simple_chatbot('I need some advice')
      "Sure, what kind of advice do you need?"
      >>> simple_chatbot('Where can I find good tutorials')
      "You can find tutorials online or join coding communities to get help from experienced coders. StackOverflow and Cod Academy are great resources."
      """
      states = {
          'state0': {
              'name': 'state0',
              'message': 'Hello! How can I help you?',
              'replies': {'I need some advice': 'state1', 'Can you answer my questions?': 'state2'}
          },
          'state1': {
              'name': 'state1',
              'message': 'Sure, what kind of advice do you need?',
              'replies': {'Career advice': 'state3', 'Health advice': 'state4'}
          },
          'state2': {
              'name': 'state2',
              'message': 'Yes, I\'ll do my best! What do you want to know?',
              'replies': {'Where can I find good tutorials': 'state5', 'Why is coding so hard': 'state6'}
          },
          'state3': {
              'name': 'state3',
              'message': 'It is always a good idea to research the field you are interested in and creating a plan to learn the skills that are required. Make sure to contact professionals in the field to understand their experience.',
              'replies': {}
          },
          'state4': {
              'name': 'state4',
              'message': 'Focus on eating healthy and staying active. Make sure to consult a medical professional if you have any concerns.',
              'replies': {}
          },
          'state5': {
              'name': 'state5',
              'message': 'You can find tutorials online or join coding communities to get help from experienced coders. StackOverflow and Cod Academy are great resources.',
              'replies': {}
          },
          'state6': {
              'name': 'state6',
              'message': 'Coding can be challenging, especially at first. Just remember that with practice, patience and problem solving skills you can overcome the obstacles.',
              'replies': {}
          }
      }
      
      current_state = states['state0']
      while True:
          if user_input in current_state['replies']:
              next_state = current_state['replies'][user_input]
              current_state = states[next_state]
              if not current_state['replies']:
                  return current_state['message']
          else:
              return "I don't understand what you mean. Please try again."
  
output:     if user_input in current_state['replies']:
          next_state = current_state['replies'][user_input]
          current_state = states[next_state]
          if not current_state['replies']:
              return current_state['message']
      else:
          return "I don't understand what you mean. Please try again."