Question: first name of the leader of britains lib dems
[{'answer': 'Vince Cable', 'provenance': [{'wikipedia_id': '8928515', 'title': 'Leader of the Liberal Democrats', 'start_paragraph_id': 3, 'start_character': 361, 'end_paragraph_id': 3, 'end_character': 372, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]