Question: how many arms of government are there in nigeria
[{'answer': 'three', 'provenance': [{'wikipedia_id': '21387', 'title': 'Federal government of Nigeria', 'start_paragraph_id': 1, 'start_character': 49, 'end_paragraph_id': 1, 'end_character': 54, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]