Question: who is the most successful club in spain
[{'answer': 'Real Madrid', 'provenance': [{'wikipedia_id': '17937080', 'title': 'Football records and statistics in Spain', 'start_paragraph_id': 5, 'start_character': 36, 'end_paragraph_id': 5, 'end_character': 47, 'bleu_score': 1.0, 'section': 'Section::::League.:Titles.\n'}]}]