input: 
  def chatbot_state_machine():
      """Create a simple chatbot using Python and state diagrams. The chatbot is initialized in 'state0' and transitions between different states based on user input. If the user input matches a reply in the current state, the chatbot transitions to the corresponding state. The conversation ends when the chatbot reaches a terminal state, which doesn't have any replies.
      Example:
      for chatbot_state_machine() and the following conversation:
      >> user message: 'I need some advice'
      >> user message: 'Career advice'
      Output:
      Goodbye!
      Conversation:
      Hello! How can I help you?
      I need some advice
      Sure, what kind of advice do you need?
      Career advice
      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.
      """
  
output:     state = 'state0'
      states = {
          'state0': {
              'replies': {
                  'I need some advice': 'state1'
              },
              'message': 'Hello! How can I help you?'
          },
          'state1': {
              'replies': {
                  'Career advice': 'state2'
              },
              'message': 'Sure, what kind of advice do you need?'
          },
          'state2': {
              'replies': {},
              '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.'
          }
      }
  
      print(states[state]['message'])
      while state in states:
          user_input = input('>> user message: ')
          if user_input in states[state]['replies']:
              state = states[state]['replies'][user_input]
              print(states[state]['message'])
          else:
              print("I didn't understand that. Can you rephrase?")
  
      print("Goodbye!")