Question: who has the biggest twitter following in the world
[{'answer': 'American singer Katy Perry', 'provenance': [{'wikipedia_id': '52247588', 'title': 'List of most-followed Twitter accounts', 'start_paragraph_id': 1, 'start_character': 119, 'end_paragraph_id': 1, 'end_character': 145, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '52247588', 'title': 'List of most-followed Twitter accounts', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 264, 'bleu_score': 0.6292179933799771, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15011404263004292443}, 'section': 'Section::::Abstract.'}]}]