Question: how many runways are there at gatwick airport
[{'answer': 'a single - runway airport', 'provenance': [{'wikipedia_id': '101359', 'title': 'Gatwick Airport', 'start_paragraph_id': 21, 'start_character': 20, 'end_paragraph_id': 21, 'end_character': 52, 'bleu_score': 1.0, 'section': 'Section::::Operations.:Flight movements.\n'}]}, {'provenance': [{'wikipedia_id': '101359', 'title': 'Gatwick Airport', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 509, 'bleu_score': 0.7465034817992651, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6354247068971968029}, 'section': 'Section::::Abstract.'}]}]