Question: who is the longest serving actor in emmerdale
[{'answer': 'Chris Chittell', 'provenance': [{'wikipedia_id': '192572', 'title': 'Emmerdale', 'start_paragraph_id': 42, 'start_character': 1781, 'end_paragraph_id': 42, 'end_character': 1795, 'bleu_score': 1.0, 'section': 'Section::::Setting and characters.\n'}]}]