Question: what does brahmaputra form after its meeting with the ganga
[{'answer': 'Padma River', 'provenance': [{'wikipedia_id': '183522', 'title': 'Brahmaputra River', 'start_paragraph_id': 20, 'start_character': 325, 'end_paragraph_id': 20, 'end_character': 336, 'bleu_score': 1.0, 'section': 'Section::::Geography.:Course.:Bangladesh.\n'}]}, {'provenance': [{'wikipedia_id': '183522', 'title': 'Brahmaputra River', 'start_paragraph_id': 20, 'start_character': 0, 'end_paragraph_id': 20, 'end_character': 630, 'bleu_score': 0.912375284825309, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8967098557168412327}, 'section': 'Section::::Geography.:Course.:Bangladesh.\n'}]}]