Question: how many paintings of sunflowers did van gogh paint
[{'answer': 'two', 'provenance': [{'wikipedia_id': '1087141', 'title': 'Sunflowers (Van Gogh series)', 'start_paragraph_id': 1, 'start_character': 66, 'end_paragraph_id': 1, 'end_character': 69, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1087141', 'title': 'Sunflowers (Van Gogh series)', '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': 15019057002460457555}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1087141', 'title': 'Sunflowers (Van Gogh series)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 862, 'bleu_score': 0.9868845362499331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15019057002460457555}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1087141', 'title': 'Sunflowers (Van Gogh series)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Sunflowers (original title, in French: Tournesols) is the name of two series of still life paintings by the Dutch painter Vincent van Gogh', 'Sunflowers (original title, in French: Tournesols) is the name of two series of still life paintings by the Dutch painter Vincent van Gogh.', 'Sunflowers (original title, in French: Tournesols) is the name of two series of still life paintings by the Dutch painter Vincent van Gogh.']}}]}]