Task: Question Generation
Input (English): Passage: The Conference of Ambassadors drew the first demarcation line on June 18. The line, drawn about 5 km  west of the Warsaw - Saint Petersburg Railway, was based on the military situation on the ground rather than ethnic composition. Neither Poles nor Lithuanians were content with the line. The Polish Ministry of Foreign Affairs rejected the line as it would require the Polish forces to retreat up to 35 km . The Lithuanians protested leaving Vilnius and Hrodna under Polish control. As German volunteers were departing from Lithuania and Lithuanian forces were preoccupied with battles against the Soviets in northern Lithuania, Poland mounted an offensive on 100 km  wide front moving 20-30 km  deeper into the Lithuanian territory. On July 18, Ferdinand Foch proposed the second demarcation line, known as the Foch Line. It was approved by the Entente on July 26. The Lithuanians were informed about the new line only on August 3. Two major modifications favorable to the Poles were made: the Suwałki Region was assigned to Poland and the entire line was moved about 7 km  west. Again, both Poles and Lithuanians protested the line as it would require them to withdraw their armies from the Vilnius and Suwałki Regions respectively. German administration, which had not yet retreated from the Suwałki Region, also opposed the Foch Line. The new line did not immediately halt the hostilities. After a couple of Polish attacks on July 29 and August 2, the front stabilized.
Output (English): Approximately how many km west of the Warsaw-Saint Petersburg Railway did the second line end up being?