Question: where is the positive electrode placed in lead iii
[{'answer': 'right or left leg', 'provenance': [{'wikipedia_id': '3994665', 'title': "Einthoven's triangle", 'start_paragraph_id': 6, 'start_character': 89, 'end_paragraph_id': 6, 'end_character': 106, 'bleu_score': 1.0, 'section': 'Section::::Lead placements.\n'}]}, {'provenance': [{'wikipedia_id': '3994665', 'title': "Einthoven's triangle", 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 179, 'bleu_score': 0.8686624666729521, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1275662406239775583}, 'section': 'Section::::Lead placements.\n'}]}]