Question: how many seasons of northern exposure are there
[{'answer': '6', 'provenance': [{'wikipedia_id': '235429', 'title': 'Northern Exposure', 'start_paragraph_id': 4, 'start_character': 325, 'end_paragraph_id': 4, 'end_character': 326, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}]