Question: when did the first episode of riverdale air
[{'answer': 'January 26 , 2017', 'provenance': [{'wikipedia_id': '49281386', 'title': 'Riverdale (2017 TV series)', 'start_paragraph_id': 3, 'start_character': 22, 'end_paragraph_id': 3, 'end_character': 39, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]