Question: the initial unification of upper and lower egypt took place during which period
[{'answer': 'c. 3000 BC', 'provenance': [{'wikipedia_id': '49463', 'title': 'Upper and Lower Egypt', 'start_paragraph_id': 6, 'start_character': 54, 'end_paragraph_id': 6, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Structure.\n'}]}, {'answer': '3000 BC', 'provenance': [{'wikipedia_id': '49463', 'title': 'Upper and Lower Egypt', 'start_paragraph_id': 6, 'start_character': 57, 'end_paragraph_id': 6, 'end_character': 64, 'bleu_score': 1.0, 'section': 'Section::::Structure.\n'}]}, {'provenance': [{'wikipedia_id': '49463', 'title': 'Upper and Lower Egypt', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 638, 'bleu_score': 0.9826823455989031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11378728892912334483}, 'section': 'Section::::Structure.\n'}]}, {'provenance': [{'wikipedia_id': '49463', 'title': 'Upper and Lower Egypt', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11378728892912334483}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '49463', 'title': 'Upper and Lower Egypt', 'section': 'Section::::Structure.\n', 'start_paragraph_id': 6, 'end_paragraph_id': 6, 'meta': {'evidence_span': ['The two kingdoms of Upper and Lower Egypt were united c. 3000 BC', 'The two kingdoms of Upper and Lower Egypt were united c. 3000 BC, but each maintained its own regalia: the "hedjet" or White Crown for Upper Egypt and the "deshret" or Red Crown for Lower Egypt', 'The two kingdoms of Upper and Lower Egypt were united c. 3000 BC, but each maintained its own regalia: the "hedjet" or White Crown for Upper Egypt and the "deshret" or Red Crown for Lower Egypt.']}}]}]