Question: what is hero's last name in big hero 6
[{'answer': 'Hamada', 'provenance': [{'wikipedia_id': '39345917', 'title': 'Big Hero 6 (film)', 'start_paragraph_id': 1, 'start_character': 342, 'end_paragraph_id': 1, 'end_character': 348, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '39345917', 'title': 'Big Hero 6 (film)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 609, 'bleu_score': 0.9806740509884301, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17887121380113520002}, 'section': 'Section::::Abstract.'}]}]