Question: how many league titles does manchester united have
[{'answer': '20', 'provenance': [{'wikipedia_id': '19961', 'title': 'Manchester United F.C.', 'start_paragraph_id': 2, 'start_character': 96, 'end_paragraph_id': 2, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]