Question: who won the universal title at royal rumble 2018
[{'answer': 'Brock Lesnar', 'provenance': [{'wikipedia_id': '56756597', 'title': 'WWE Greatest Royal Rumble', 'start_paragraph_id': 2, 'start_character': 121, 'end_paragraph_id': 2, 'end_character': 133, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '56756597', 'title': 'WWE Greatest Royal Rumble', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 417, 'bleu_score': 0.6654242286878, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3358121284536162998}, 'section': 'Section::::Abstract.'}]}]