Question: who killed the witch king in the book
[{'answer': 'Éowyn', 'provenance': [{'wikipedia_id': '22041480', 'title': 'Witch-king of Angmar', 'start_paragraph_id': 18, 'start_character': 248, 'end_paragraph_id': 18, 'end_character': 253, 'bleu_score': 1.0, 'section': 'Section::::Literature.:Campaign against Gondor.\n'}]}, {'answer': 'Meriadoc Brandybuck', 'provenance': [{'wikipedia_id': '22041480', 'title': 'Witch-king of Angmar', 'start_paragraph_id': 18, 'start_character': 457, 'end_paragraph_id': 18, 'end_character': 476, 'bleu_score': 1.0, 'section': 'Section::::Literature.:Campaign against Gondor.\n'}]}, {'provenance': [{'wikipedia_id': '22041480', 'title': 'Witch-king of Angmar', 'start_paragraph_id': 18, 'start_character': 0, 'end_paragraph_id': 18, 'end_character': 779, 'bleu_score': 0.985964042079227, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10952852796383127131}, 'section': 'Section::::Literature.:Campaign against Gondor.\n'}]}]