Question: name of all four houses in harry potter
[{'answer': 'Gryffindor', 'provenance': [{'wikipedia_id': '45324', 'title': 'Hogwarts', 'start_paragraph_id': 21, 'start_character': 88, 'end_paragraph_id': 21, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::Houses.\n'}]}, {'answer': 'Slytherin', 'provenance': [{'wikipedia_id': '45324', 'title': 'Hogwarts', 'start_paragraph_id': 21, 'start_character': 108, 'end_paragraph_id': 21, 'end_character': 117, 'bleu_score': 1.0, 'section': 'Section::::Houses.\n'}]}, {'answer': 'Ravenclaw', 'provenance': [{'wikipedia_id': '45324', 'title': 'Hogwarts', 'start_paragraph_id': 21, 'start_character': 126, 'end_paragraph_id': 21, 'end_character': 135, 'bleu_score': 1.0, 'section': 'Section::::Houses.\n'}]}, {'answer': 'Hufflepuff', 'provenance': [{'wikipedia_id': '45324', 'title': 'Hogwarts', 'start_paragraph_id': 21, 'start_character': 146, 'end_paragraph_id': 21, 'end_character': 156, 'bleu_score': 1.0, 'section': 'Section::::Houses.\n'}]}, {'provenance': [{'wikipedia_id': '45324', 'title': 'Hogwarts', 'start_paragraph_id': 45, 'start_character': 0, 'end_paragraph_id': 45, 'end_character': 1115, 'bleu_score': 0.9893895451459531, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3328377974774361835}, 'section': 'Section::::Student life.\n'}]}]