Question: who plays tom riddle in harry potter and the half blood prince
[{'answer': 'Frank Stephenson Dillane', 'provenance': [{'wikipedia_id': '40974652', 'title': 'Frank Dillane', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 24, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '40974652', 'title': 'Frank Dillane', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 308, 'bleu_score': 0.8614963829915381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7255938538586026062}, 'section': 'Section::::Abstract.'}]}]