Question: what is the theme of brics summit 2018
[{'answer': "' BRICS in Africa"}, {'provenance': [{'wikipedia_id': '55150046', 'title': '10th BRICS summit', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 348, 'bleu_score': 0.875929065456104, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11631913281707467371}, 'section': 'Section::::Abstract.'}]}]