Question: how many engines does the biggest plane have
[{'answer': 'four', 'provenance': [{'wikipedia_id': '181173', 'title': 'Airbus A380', 'start_paragraph_id': 12, 'start_character': 17, 'end_paragraph_id': 12, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]