Question: what fraction of congress must approve an amendment
[{'answer': 'two - thirds', 'provenance': [{'wikipedia_id': '31650', 'title': 'Article Five of the United States Constitution', 'start_paragraph_id': 24, 'start_character': 972, 'end_paragraph_id': 24, 'end_character': 987, 'bleu_score': 1.0, 'section': 'Section::::Ratification deadline and extension.:Extensions.\n'}]}, {'provenance': [{'wikipedia_id': '31650', 'title': 'Article Five of the United States Constitution', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 810, 'bleu_score': 0.7429402018508751, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9895578307869660291}, 'section': 'Section::::Abstract.'}]}]