Question: what were the pigs names in animal farm
[{'answer': 'Snowball and Napoleon', 'provenance': [{'wikipedia_id': '620', 'title': 'Animal Farm', 'start_paragraph_id': 6, 'start_character': 394, 'end_paragraph_id': 6, 'end_character': 415, 'bleu_score': 1.0, 'section': 'Section::::Plot summary.\n'}]}]