Question: which city is situated at the confluence of the yamuna and ganga
[{'answer': 'Allahabad', 'provenance': [{'wikipedia_id': '6855474', 'title': 'Triveni Sangam', 'start_paragraph_id': 2, 'start_character': 40, 'end_paragraph_id': 2, 'end_character': 49, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6855474', 'title': 'Triveni Sangam', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 331, 'bleu_score': 0.746773030158547, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 832179686386737603}, 'section': 'Section::::Triveni Sangam in Prayagraj (Allahabad).\n'}]}]