Question: how many number 1 hits did van halen have
[{'answer': 'thirteen'}, {'provenance': [{'wikipedia_id': '11092911', 'title': 'Van Halen discography', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 489, 'bleu_score': 0.860225002191896, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11584055556420142177}, 'section': 'Section::::Abstract.'}]}]