Question: how many episodes in designated survivor season 1
[{'answer': '21', 'provenance': [{'wikipedia_id': '54588442', 'title': 'Designated Survivor (season 1)', 'start_paragraph_id': 1, 'start_character': 104, 'end_paragraph_id': 1, 'end_character': 106, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]