Question: who becomes headmaster after the battle of hogwarts
[{'answer': 'McGonagall', 'provenance': [{'wikipedia_id': '947583', 'title': 'Hogwarts staff', 'start_paragraph_id': 11, 'start_character': 846, 'end_paragraph_id': 11, 'end_character': 856, 'bleu_score': 1.0, 'section': 'Section::::Notable teachers and staff members.:Filius Flitwick.\n'}]}, {'provenance': [{'wikipedia_id': '947583', 'title': 'Hogwarts staff', 'start_paragraph_id': 24, 'start_character': 0, 'end_paragraph_id': 24, 'end_character': 2640, 'bleu_score': 0.9702779799866941, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15633896634533400480}, 'section': 'Section::::Notable teachers and staff members.:Minerva McGonagall.\n'}]}]