Which album has stayed on the Billboard 200 chart the longest?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q188819', 'id': 0, 'label': 'Billboard 200'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q485240', 'id': 1, 'label': 'Billboard'}], 'links': [{'name_': 'P123', 'source': 0, 'target': 1, 'label': 'publisher'}]}