Question: Which ground force of the Austro-Hungarian Dual Monarchy did Jan Romer joined 

<P0-S0> The People's Liberation Army Ground Force (PLAGF) () is the land-based service branch of the People's Liberation Army and it is the largest and oldest branch of the entire Chinese armed forces. <P0-S1>  The PLAGF can trace its lineage from 1927; however, it was not officially established until 1948. <P0-S2>  As of 2016, the PLAGF has a strength of 1,600,000 personnel making it the largest standing army in the world. <P0-S3>  In addition, the People's Liberation Army Ground Force has an estimated 510,000 strong reserve force. <SEP> <P1-S0> Jan Romer (1869 in Lwów – 1934 in Warsaw) was a Polish general and military commander. <P1-S1>  Studied in Mödling and joined the Austro-Hungarian Army. <P1-S2>  During the First World War fought at the battle of Limanowa (1914) and battle of Gorlice (1914), was wounded twice. <P1-S3>  Later he joined the newly recreated Polish Army. <P1-S4>  During Polish-Ukrainian War he fought in the liberation of Lwów. <P1-S5>  In Polish-Soviet War, commanded the Cavalry Division at the Battle of Koziatyn (April 25-April 27, 1920), one of the most spectacular raids of the Polish cavalry, during the Polish advance towards Kiev. <P1-S6>  His troops fought against the Soviet cavalry elite "Konarmia" of Semyon Budyonny. <P1-S7>  He commanded the Polish 13th Infantry Division during the Battle of Komarów (August 31, 1920). <P1-S8>  Respected by Józef Piłsudski, he was among the first group military personas who confirmed the decoration of Virtuti Militari, highest Polish military decoration, restored after the recreation of the Second Polish Republic, and he himself received the Commander's Cross of that award. <P1-S9>  Held position of Inspector of the Army after the war. <P1-S10>  Buried in Powązki Cemetery in Warsaw. <SEP> <P2-S0> The People's Army of Vietnam (PAVN; Vietnamese: "Quân Đội Nhân Dân Việt Nam" ), also known as the Vietnamese People's Army (VPA), is the military force of the Socialist Republic of Vietnam. <P2-S1>  The PAVN is a part of Vietnam People's Armed Forces and includes: Ground Force (including Strategic Rear Forces), Navy, Air Force, Border Defence Force, and Coast Guard. <P2-S2>  However, Vietnam does not have a specific separate Ground Force or Army branch. <P2-S3>  All ground troops, army corps, military districts and specialised arms belong to the Ministry of Defence, directly under command of the Central Military Commission, Minister of Defence, and General Staff of the Vietnam People's Army. <P2-S4>  The military flag of the PAVN is the flag of the Socialist Republic of Vietnam, with the words "Quyết thắng (Determination to win)" added in yellow at the top left. <SEP> <P3-S0> The Austro-Hungarian Army (German: "Landstreitkräfte Österreich-Ungarns" ; Hungarian: "Császári és Királyi Hadsereg" ) was the ground force of the Austro-Hungarian Dual Monarchy from 1867 to 1918. <P3-S1>  It was composed of three parts: the joint army ("Gemeinsame Armee ", "Common Army", recruited from all parts of the country), the Imperial Austrian Landwehr (recruited from Cisleithania), and the Royal Hungarian Honved (recruited from Transleithania).