Question: The main character of The Pianist survives due to the help of a German army captain, who was taken prisoner by what army?

full_context: Document 1: Night (book): Night (1960) is a work by Elie Wiesel about his experience with his father in the Nazi German concentration camps at Auschwitz and Buchenwald in 1944–1945, at the height of the Holocaust toward the end of the Second World War. In just over 100 pages of sparse and fragmented narrative, Wiesel writes about the death of God and his own increasing disgust with humanity, reflected in the inversion of the parent–child relationship, as his father declines to a helpless state and Wiesel becomes his resentful teenage caregiver. "If only I could get rid of this dead weight ... Immediately I felt ashamed of myself, ashamed forever." In "Night" everything is inverted, every value destroyed. "Here there are no fathers, no brothers, no friends," a kapo tells him. "Everyone lives and dies for himself alone."
Document 2: The Pianist (memoir): The Pianist is a memoir by the Polish-Jewish pianist and composer Władysław Szpilman in which he describes his life in Warsaw in occupied Poland during World War II. After being forced with his family to live in the Warsaw ghetto, Szpilman manages to avoid deportation to the Treblinka extermination camp, and from his hiding places around the city witnesses the Warsaw ghetto uprising in 1943 and the Warsaw uprising (the rebellion by the Polish resistance) the following year. He survives in the ruined city with the help of friends and strangers, including Wilm Hosenfeld, a German army captain who admires his piano playing.
Document 3: Alexander Donat: Alexander Donat also Aleksander Donat in Polish (1905 – 16 June 1983); a chemist by training, and journalist by profession; was a Holocaust survivor imprisoned at the Warsaw Ghetto during the occupation of Poland by Nazi Germany in World War II. He became an inmate of several Nazi forced labor and concentration camps and an eye witness to the Holocaust in Poland. After the war, Donat emigrated with his family to the United States, settling in New York City, and went on to write about his wartime experiences. He wrote "Jewish Resistance" (1964), "Holocaust Kingdom" (1965), and "The Death Camp Treblinka: a documentary" (1979), a series of memoirs devoted to these traumatic events.
Document 4: A Survivor from Warsaw: A Survivor from Warsaw, Op. 46, is a cantata by the Los Angeles-based Austrian composer Arnold Schoenberg, written in tribute to Holocaust victims. The main narration is unsung; “never should there be a pitch” to its solo vocal line, wrote the composer.
Document 5: Władysław Szpilman: Władysław Szpilman (] ; 5 December 19116 July 2000) was a Polish pianist and classical composer of Jewish descent. Szpilman is widely known as the central figure in the 2002 Roman Polanski film "The Pianist", which was based on Szpilman's autobiographical account of how he survived the German occupation of Warsaw and the Holocaust.
Document 6: Wilm Hosenfeld: Wilhelm Adalbert Hosenfeld (] ; 2 May 1895 – 13 August 1952), originally a school teacher, was a German Army officer who by the end of the Second World War had risen to the rank of "Hauptmann" (Captain). He helped to hide or rescue several Polish people, including Jews, in Nazi-occupied Poland, and helped Polish-Jewish pianist and composer Władysław Szpilman to survive, hidden, in the ruins of Warsaw during the last months of 1944, an act which was portrayed in the 2002 film The Pianist. He was taken prisoner by the Red Army and died in Soviet captivity seven years later.
Document 7: List of Polish cities damaged in World War II: As the German army retreated during the later stages of the Second World War, many of the urban areas of what is now Poland were severely damaged as a result of military action between the retreating forces of the German Wehrmacht and advancing ones of the Soviet Red Army. Other cities were deliberately destroyed by the German forces. One of the most famous of these planned destructions was the razing of Warsaw, the capital of Poland. While extensively damaged by the failed Warsaw Ghetto Uprising and Warsaw Uprising, the city later underwent a planned demolition by German forces under order from Adolf Hitler and high officials within the Nazi government. On 17 October 1944, SS chief Heinrich Himmler famously stated, "The city must completely disappear from the surface of the earth and serve only as a transport station for the Wehrmacht." Before they were stopped by the advancing Red Army, 85% of the city had been taken out. Warsaw was far from the worst off after the Nazi retreat; 97% of Jasło and 100% of Polanów were reduced to rubble. Other towns such as Wałcz fared better, with only a quarter of the city being destroyed. Ancient historical buildings in Polish cities were not spared; for example, Trzemeszno's Romanesque basilica of 1130-45 was burnt down in 1945.
Document 8: Wilhelm Dichter: Wilhelm Dichter is a Polish American writer who has written three novels based on his life. He was born in 1935 in Borysław (in modern-day Ukraine), where he survived the war. His father had died, and he and his mother (remarried after the war) came to live in Poland toward the end of 1944. He finished his studies at the Warsaw Polytechnic, where he earned his doctorate in mechanical engineering and worked for 13 years until 1968. The antisemitic campaign in 1968 in Poland provided the opportunity for him and his family to emigrate, through Vienna and Rome, eventually settling in the United States. As an expert in ballistics, he worked at Colt Firearms in the R&D division on Long Island, New York, and later in Hartford Connecticut. In 1978, he made a transition to the field of image processing, becoming an image processing algorithm design specialist at the Linotype-Hell company. Wilhelm Dichter is now retired from his engineering and scientific work. When he is not writing, Wilhelm and his wife Ola spend quality time with their grandchildren. He and Ola live in the Boston area.
Document 9: Warsaw Ghetto Uprising: The Warsaw Ghetto Uprising (Yiddish: אױפֿשטאַנד אין װאַרשעװער געטאָ‎ ; Polish: "powstanie w getcie warszawskim" ; German: "Aufstand im Warschauer Ghetto" ) was the 1943 act of Jewish resistance that arose within the Warsaw Ghetto in German-occupied Poland during World War II, and which opposed Nazi Germany's final effort to transport the remaining Ghetto population to Treblinka. The uprising started on 19 April when the Ghetto refused to surrender to the police commander SS-Brigadeführer Jürgen Stroop, who then ordered the burning of the Ghetto, block by block, ending on 16 May. A total of 13,000 Jews died, about half of them burnt alive or suffocated. German casualties are not known, but were not more than 300. It was the largest single revolt by Jews during World War II.
Document 10: Felix Landau: Felix Landau (May 21, 1910, Vienna, Austria – April 4, 1983), was a SS Hauptscharführer, a member of an Einsatzkommando during World War II, based first in Lwów, Poland (today Lviv, Ukraine), and later in Drohobycz. He was a "central figure in the Nazi program of the extermination of Galician Jews". He is known for his daily diary and for temporarily sparing the life of the Jewish artist Bruno Schulz in 1942. Landau liked Schulz's art and supplied him with protection and extra food. In return, he ordered the artist to paint a set of murals for his young son's bedroom, depicting scenes from the Brothers Grimm fairy tales. Landau also was the SS officer assigned to watch over Maria Altmann, the subject of the film Woman in Gold (2015).
Document 11: Elie Wiesel: Eliezer "Elie" Wiesel KBE ( , Yiddish: אליעזר ויזל‎ , "Elyezer Vizel"; September 30, 1928 – July 2, 2016) was a Romanian-born American Jewish writer, professor, political activist, Nobel Laureate and Holocaust survivor. He was the author of 57 books, written mostly in French and English, including "Night", a work based on his experiences as a prisoner in the Auschwitz and Buchenwald concentration camps.
Document 12: Chaim Itsl Goldstein: Chaim Itsl Goldstein, also known as Charles Goldstein, was born in Warsaw, Poland. He was a worker and a leftist activist. He emigrated to Paris in 1930. During World War II, Goldstein was arrested and transported to Auschwitz concentration camp. In October 1943, he was taken to Warsaw, where he worked in the Warsaw Ghetto ruins after the unsuccessful Warsaw Ghetto Uprising. Goldstein was liberated during Warsaw Uprising and participated in it. After the uprising's failure, he hid in a bunker in the destroyed and deserted city. His memoirs "Zibn in bunḳer" (Eng. "Seven in the bunker", known also as "The Bunker") have been published in Yiddish, Hebrew, English, French and Polish.
Document 13: Return to the Hiding Place: Return to the Hiding Place (2013) is a film based upon the factual accounting of Hans Poley's World War II encounter with Corrie ten Boom, his involvement in the Dutch resistance and the wartime harboring of Jewish refugees. A non-Jewish fugitive himself, for refusing to pledge his allegiance to the Nazi party; Poley was the first person hidden from the Nazis in Ten Boom House, which today is a museum in Haarlem, Netherlands. The film is adapted, in part, from Poley's book, "Return to the Hiding Place" (1993), personal recollections, relayed to screenwriter Dr. Peter C. Spencer, and research from the Dutch National Archives. The film is neither a prequel, nor a sequel to the 1975 film, "The Hiding Place"; rather, "Return to the Hiding Place" is a congruent accounting of Dutch underground resistance efforts from Hans Poley's perspective. It was directed by Peter C. Spencer and starred John Rhys-Davies, Mimi Sagadin and Craig Robert Young.
Document 14: Oskar Schindler: Oskar Schindler (28 April 1908 – 9 October 1974) was a German industrialist, spy, and member of the Nazi Party who is credited with saving the lives of 1,200 Jews during the Holocaust by employing them in his enamelware and ammunitions factories, which were located in occupied Poland and the Protectorate of Bohemia and Moravia. He is the subject of the 1982 novel "Schindler's Ark" and its 1993 film adaptation, "Schindler's List", which reflected his life as an opportunist initially motivated by profit, who came to show extraordinary initiative, tenacity, and dedication to save the lives of his Jewish employees.
Document 15: Zofia Posmysz: Zofia Posmysz (born 23 August 1923) is a Polish author. In 1942 she was arrested by the Gestapo on suspicion of distributing anti-Nazi leaflets. She survived the Auschwitz and Birkenau concentration camps and afterwards gained a position with Polish national radio. She is the author of several works including the 1959 radio play "The Passenger in Cabin 45", which was adapted into her 1962 novel "Passenger", and into a television play and film "The Passenger". Composer Mieczysław Weinberg used the story as the basis for his 1968 opera "The Passenger".
ground_truth: Red Army