Question: where did the chargers first play at in san diego
[{'answer': 'Balboa Stadium', 'provenance': [{'wikipedia_id': '9984506', 'title': 'History of the San Diego Chargers', 'start_paragraph_id': 1, 'start_character': 369, 'end_paragraph_id': 1, 'end_character': 383, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '9984506', 'title': 'History of the San Diego Chargers', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 588, 'bleu_score': 0.768742386020798, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6682526657835116239}, 'section': 'Section::::Abstract.'}]}]