Detailed Instructions: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Q: Passage: Ostashenko was born on 19 June 1896 in the village of Bolshaya Lyubshchina, Yanovichskoy volost, Vitebsky Uyezd, Vitebsk Governorate to a peasant family. He graduated from four grades at a gymnasium. During World War I, he was mobilized for military service on 7 August 1915, being sent to the 4th Company of the Reserve Battalion of the Petrograd Lifeguard Regiment in Petrograd. With the battalion, he fought with the Southwestern Front between July 1916 and February 1917, then returned to Petrograd before being demobilized on 13 March 1918. In July, he volunteered for the Red Army, serving in the Vitebsky Uyezd military commissariat as a clerk and instructor organizer. From May 1919 Ostashenko served as a Red Army man and political soldier – a Communist mobilized to conduct political work in the army – in the march battalion of the Vitebsk Reserve Regiment. From July he served as an assistant platoon commander in the 84th Rifle Regiment of the 10th Rifle Division, which fought against the Northwestern Army near Petrograd as part of the 15th Army of the Western Front. He entered the Smolensk Commanders' Infantry Courses in November and upon graduation in June 1920 became a platoon commander in the Rzhev-based 2nd Reserve Regiment. This assignment proved to be brief and a month later, Ostashenko became adjutant of the 4th Landing Detachment for armored trains with the Western Front. He fought with the detachment, which provided landing parties for armored trains, in the Polish–Soviet War and was wounded twice.
 Link Information: With 5 million inhabitants in 2012, it is Russia's second-largest city after Moscow. Question: What is the modern-day population of the city whose Lifeguard Regiment Ostashenko joined in 1915?
A:
Answer: 5 million