Task: Question Understanding
Input (English): Passage: After the failure of the coup in Kaunas, there were numerous small border incidents. On September 19, 1919, Polish troops attacked Gelvonai and encroached towards Ukmergė. On several occasions fights broke out regarding strategically important bridge over the Šventoji River near Vepriai. In October, when main Lithuanian forces were deployed against the Bermontians in northwestern Lithuania, the attacks intensified. Poles captured Salakas on October 5 and attacked Kapčiamiestis on October 12. The front stabilized, but harassment of border guards and local villagers continued throughout late 1919 and early 1920. In March 1920, the Poles attacked along the railroad stations in Kalkūni and Turmantas. The situation was investigated by British and French observers and reported to the Entente. The situation somewhat improved only in late spring 1920 when most Polish troops were deployed in Ukraine during the Polish-Soviet War. At the time Lithuania faced a severe budget crisis - in 1919 its revenue was 72 million while expenses reached 190 million German marks. While the government was struggling to obtain financial assistance and loans, deep cuts affected the army. Instead of increasing its armed forces to 40,000 men, Lithuania was forced to cut them to about 25,000.
Question: In what year were Lithuanian forces deployed against the Bermontians in northwestern Lithuania?
Output (English): date