Хитрый выигрыш с конем против двух ладей

{"document": [{"text": [{"type": "string", "attributes": {}, "string": "Предлагаю решить следующую шахматную задачку."}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "У черных две ладьи против белого коня."}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "Однако белые начинают и ставят мат в несколько ходов."}], "attributes": []}, {"text": [{"type": "attachment", "attributes": {"presentation": "gallery"}, "attachment": {"caption": "", "contentType": "image/jpeg", "filename": "2.jpg", "filesize": 241203, "height": 563, "pic_id": 392834, "url": "/files/article_image/2023/01/27/2_AwkFDnE.jpeg", "width": 561}}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "Решение "}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "показываю"}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "далее."}], "attributes": []}, {"text": [{"type": "attachment", "attributes": {"presentation": "gallery"}, "attachment": {"caption": "", "contentType": "image/jpeg", "filename": "3.jpg", "filesize": 241728, "height": 561, "pic_id": 392837, "url": "/files/article_image/2023/01/27/3_WILJ9Yy.jpeg", "width": 560}}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "Белые дают шах ферзем."}], "attributes": []}, {"text": [{"type": "attachment", "attributes": {"presentation": "gallery"}, "attachment": {"caption": "", "contentType": "image/jpeg", "filename": "4.jpg", "filesize": 243739, "height": 559, "pic_id": 392838, "url": "/files/article_image/2023/01/27/4_FoSpJgG.jpeg", "width": 557}}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "Черные отходят королем."}], "attributes": []}, {"text": [{"type": "string", "attributes": {}, "string": "Белые дают шах ферзем и далее ставят мат."}], "attributes": []}], "selectedRange": [259, 259]}