Question: where does the paraguay river start and end
[{'answer': 'Paraná River', 'provenance': [{'wikipedia_id': '1032278', 'title': 'Paraguay River', 'start_paragraph_id': 1, 'start_character': 306, 'end_paragraph_id': 1, 'end_character': 318, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River north of Corrientes and Resistencia'}, {'answer': 'Parecis plateau , Mato Grosso , Brazil'}, {'provenance': [{'wikipedia_id': '1032278', 'title': 'Paraguay River', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 354, 'bleu_score': 0.87540210596635, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9930146940471363203}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1032278', 'title': 'Paraguay River', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9930146940471363203}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '623579', 'title': 'Paraná River', 'section': 'Section::::Course.\n', 'start_paragraph_id': 6, 'end_paragraph_id': 6, 'meta': {'evidence_span': ['fter merging with the Iguazu, the Paraná then becomes the natural border between Paraguay and Argentina. Overlooking the Paraná River from Encarnación, Paraguay, across the river, is downtown Posadas, Argentina', "After merging with the Iguazu, the Paraná then becomes the natural border between Paraguay and Argentina. Overlooking the Paraná River from Encarnación, Paraguay, across the river, is downtown Posadas, Argentina. The river continues its general southward course for about before making a gradual turn to the west for another , and then encounters the Paraguay River, the largest tributary along the course of the river. Before this confluence the river passes through a second major hydroelectric project, the Yaciretá Dam, a joint project between Paraguay and Argentina. The massive reservoir formed by the project has been the source of a number of problems for people living along the river, most notably the poorer merchants and residents in the low-lying areas of Encarnación, a major city on the southern border of Paraguay. River levels rose dramatically upon completion of the dam, flooding out large sections of the city's lower areas. From the confluence with the Paraguay River, the Paraná again turns to the", 'Overlooking the Paraná River from Encarnación, Paraguay, across the river, is downtown Posadas, Argentina. The river continues its general southward course for about before making a gradual turn to the west for another , and then encounters the Paraguay River, the largest tributary along the course of the river. Before this confluence the river passes through a second major hydroelectric project, the Yaciretá Dam, a joint project between Paraguay and Argentina. T']}}]}]