Definition: In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.
Input: Question: How long had the Khanate of Bukhara been in existence when the Russians occupied the territory? Passage:In the spring of 1868 he made his first trip to the edge of Central Asia, traveling with a Russian merchant, Vasilii Alekseich, by steamboat down the Volga to Samara, then by carriage to Orenburg, which at the time was the base for Russian military operations The Russians had occupied the Khanate of Bukhara in 1866 and were advancing toward Samarkand. In 1868, Schuyler was a guest of Tolstoi for a week at his estate at Yasnaya Polyana, at the time when Tolstoi was finishing War and Peace. He helped Tolstoi rearrange his library, and went hunting with him. Tolstoi, who was interested in public education in the United States, asked Schuyler for copies of American primers and school textbooks. Schuyler received Tolstoi's permission to translate his novel The Cossacks into English. In 1869, the new Administration of President Ulysses Grant removed Schuyler from his post in Moscow and replaced him with a political appointee. Schuyler was able to obtain a post as consul to the Russian port of Reval (now Tallinn). In November, 1869, President Grant appointed a new Minister to Russia, Andrew Curtin, a former Governor of Pennsylvania who knew nothing of Russia. Curtin was impressed by Schuyler and appointed him as the secretary of the American legation in St. Petersburg, a post which Schuyler held until 1876.

Output:
In the spring of 1868 he made his first trip to the edge of Central Asia, traveling with a Russian merchant, Vasilii Alekseich, by steamboat down the Volga to Samara, then by carriage to Orenburg, which at the time was the base for Russian military operations The Russians had occupied the Khanate of Bukhara in 1866 and were advancing toward Samarkand