Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
Example: Context: Architecturally, the school has a Catholic character. Atop the Main Building's gold dome is a golden statue of the Virgin Mary. Immediately in front of the Main Building and facing it, is a copper statue of Christ with arms upraised with the legend 'Venite Ad Me Omnes'. Next to the Main Building is the Basilica of the Sacred Heart. Immediately behind the basilica is the Grotto, a Marian place of prayer and reflection. It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858. At the end of the main drive (and in a direct line that connects through 3 statues and the Gold Dome), is a simple, modern stone statue of Mary.
Question: To whom did the Virgin Mary allegedly appear in 1858 in Lourdes France?
Example solution: Saint Bernadette Soubirous
Example explanation: This is the correct answer. Because the question is asking for the name of the person and following sentence from the passage answers it: It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858.

Problem: Context: In the north of the region is the Sailughem Mountains, also known as Kolyvan Altai, which stretch northeast from 49 N and 86 E towards the western extremity of the Sayan Mountains in 51 60 N and 89 E. Their mean elevation is 1,500 to 1,750 m. The snow-line runs at 2,000 m on the northern side and at 2,400 m on the southern, and above it the rugged peaks tower some 1,000 m higher. Mountain passes across the range are few and difficult, the chief being the Ulan-daban at 2,827 m (2,879 m according to Kozlov), and the Chapchan-daban, at 3,217 m, in the south and north respectively. On the east and southeast this range is flanked by the great plateau of Mongolia, the transition being effected gradually by means of several minor plateaus, such as Ukok plateau (2,380 m) with Pazyryk Valley, Chuya (1,830 m), Kendykty (2,500 m), Kak plateau (2,520 m), (2,590 m), and (2,410 m).
Question: Which mountain pass is at a higher elevation: Ulan-daban or Chapchan-daban?
Solution: chapchan-daban