Question: who hasn't won a superbowl in the nfl
[{'answer': 'Vikings', 'provenance': [{'wikipedia_id': '1345171', 'title': 'List of NFL franchise post-season droughts', 'start_paragraph_id': 3, 'start_character': 342, 'end_paragraph_id': 3, 'end_character': 349, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Falcons', 'provenance': [{'wikipedia_id': '1345171', 'title': 'List of NFL franchise post-season droughts', 'start_paragraph_id': 3, 'start_character': 171, 'end_paragraph_id': 3, 'end_character': 178, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1345171', 'title': 'List of NFL franchise post-season droughts', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 777, 'bleu_score': 0.831529894424181, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12182309030893681148}, 'section': 'Section::::Abstract.'}]}]