Who is the most covered artist?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'QUESTIONS_ENTITY', 'name_': 'Q483501', 'id': 0, 'label': 'artist'}, {'type': 'INTERNAL', 'name_': 'Q62662386', 'id': 1, 'label': 'Wolfgang Schaper'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q673767', 'id': 2, 'label': 'art competitions at the Olympic Games'}], 'links': [{'name_': 'P106', 'source': 1, 'target': 0, 'label': 'occupation'}, {'name_': 'P641', 'source': 1, 'target': 2, 'label': 'sport'}]}