[{'role': 'USR', 'utterance': "Excuse me. I'm a stranger here and lost my way."}
 {'role': 'SYS', 'utterance': 'Can I help you?'}
 {'role': 'USR', 'utterance': 'Sure. Can I get to the central department stall this way?'}
 {'role': 'SYS', 'utterance': 'uh... Yes. Turn right, then take the second turning on your left.'}
 {'role': 'USR', 'utterance': 'Is it far?'}
 {'role': 'SYS', 'utterance': "It's about fifteen minutes' walk. That's all."}
 {'role': 'USR', 'utterance': 'And do you know where the national bank is?'}]
{'role': 'SYS', 'utterance': "Yes. It's on this street. Keep walking for two blocks and it's on the corner on the right."}