Question: what was the capital of north vietnam in the mid 1950s
[{'answer': 'Hanoi', 'provenance': [{'wikipedia_id': '23550210', 'title': 'North Vietnam', 'start_paragraph_id': 8, 'start_character': 366, 'end_paragraph_id': 8, 'end_character': 371, 'bleu_score': 1.0, 'section': 'Section::::Leadership under Hồ Chí Minh (1945–69).:Proclamation of the republic.\n'}]}]