Question: who is playing halftime show super bowl 50
[{'answer': 'Coldplay', 'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 1, 'start_character': 178, 'end_paragraph_id': 1, 'end_character': 186, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Beyoncé', 'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 1, 'start_character': 217, 'end_paragraph_id': 1, 'end_character': 224, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Bruno Mars', 'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 1, 'start_character': 229, 'end_paragraph_id': 1, 'end_character': 239, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'the British rock group Coldplay', 'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 1, 'start_character': 155, 'end_paragraph_id': 1, 'end_character': 186, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'special guest performers Beyoncé and Bruno Mars'}, {'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 1354, 'bleu_score': 0.990888145196896, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9917793820839041859}, 'section': 'Section::::Performance.\n'}]}, {'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 341, 'bleu_score': 0.9657992495762461, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9917793820839041859}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '45267196', 'title': 'Super Bowl 50 halftime show', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ["The Super Bowl 50 Halftime Show took place on February 7, 2016, at Levi's Stadium in Santa Clara, California as part of Super Bowl 50. It was headlined by the British rock group Coldplay with special guest performers Beyoncé and Bruno Mars, who previously had headlined the Super Bowl XLVII and Super Bowl XLVIII halftime shows, respectively.", 'It was headlined by the British rock group Coldplay with special guest performers Beyoncé and Bruno Mars, who previously had headlined the Super Bowl XLVII and Super Bowl XLVIII halftime shows, respectively.']}}]}]