Question: how many episodes did season 1 of this is us have
[{'answer': '18 episodes', 'provenance': [{'wikipedia_id': '50526957', 'title': 'This Is Us (TV series)', 'start_paragraph_id': 3, 'start_character': 69, 'end_paragraph_id': 3, 'end_character': 80, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '50526957', 'title': 'This Is Us (TV series)', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 219, 'bleu_score': 0.9493253852526031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16294322824923533203}, 'section': 'Section::::Abstract.'}]}]