Question: who has held the office of cm for long time
[{'answer': 'Chamling', 'provenance': [{'wikipedia_id': '1509671', 'title': 'Pawan Kumar Chamling', 'start_paragraph_id': 0, 'start_character': 12, 'end_paragraph_id': 0, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]