Question: how many characters are specified in ascii scheme
[{'answer': '128', 'provenance': [{'wikipedia_id': '586', 'title': 'ASCII', 'start_paragraph_id': 6, 'start_character': 56, 'end_paragraph_id': 6, 'end_character': 59, 'bleu_score': 1.0, 'section': 'Section::::Overview.\n'}]}, {'provenance': [{'wikipedia_id': '586', 'title': 'ASCII', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 471, 'bleu_score': 0.937535115907385, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15677826828744235777}, 'section': 'Section::::Overview.\n'}]}]