Question: this question is based on the st. louis arch video. what is the nickname given to the st. louis arch
[{'answer': 'The Gateway Arch', 'provenance': [{'wikipedia_id': '53353', 'title': 'Gateway Arch', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53353', 'title': 'Gateway Arch', 'start_paragraph_id': 1, 'start_character': 17, 'end_paragraph_id': 1, 'end_character': 612, 'bleu_score': 0.8560162403644771, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4204938633515671694}, 'section': 'Section::::Abstract.'}]}]