Question: how many episodes are there in this is us season 1
[{'answer': '18', 'provenance': [{'wikipedia_id': '52995450', 'title': 'This Is Us (season 1)', 'start_paragraph_id': 3, 'start_character': 93, 'end_paragraph_id': 3, 'end_character': 95, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]