Question: which british prime minister signed the lisbon treaty
[{'answer': 'Gordon Brown', 'provenance': [{'wikipedia_id': '24867534', 'title': 'Signing of the Treaty of Lisbon', 'start_paragraph_id': 11, 'start_character': 22, 'end_paragraph_id': 11, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Ceremony.:Location and decorations.\n'}]}, {'provenance': [{'wikipedia_id': '24867534', 'title': 'Signing of the Treaty of Lisbon', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 1071, 'bleu_score': 0.988731944750971, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6186758846038568398}, 'section': 'Section::::Ceremony.:Absence of Gordon Brown.\n'}]}]