Question: who is the longest serving mp in the uk
[{'answer': 'Winston Churchill', 'provenance': [{'wikipedia_id': '11921877', 'title': 'Records of members of parliament of the United Kingdom', 'start_paragraph_id': 32, 'start_character': 77, 'end_paragraph_id': 32, 'end_character': 94, 'bleu_score': 1.0, 'section': 'Section::::Period of service.:Longest.\n'}]}, {'provenance': [{'wikipedia_id': '11921877', 'title': 'Records of members of parliament of the United Kingdom', 'start_paragraph_id': 32, 'start_character': 0, 'end_paragraph_id': 32, 'end_character': 512, 'bleu_score': 0.979896933041101, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13613196880734963908}, 'section': 'Section::::Period of service.:Longest.\n'}]}]