What nationality was the composer of the symphonic poem Prince Rostislav ? 
Russian
Title: Prince Rostislav (poem)
Passage: Prince Rostislav (Князь Ростисла′в) is a poem by Alexey Konstantinovich Tolstoy first published in the April 1856 issue of "The Russian Messenger" (book 1, pp. 483-484), subtitled "The Ballad".
Title: Sergei Rachmaninoff
Passage: Sergei Vasilievich Rachmaninoff (Russian: Серге́й Васи́льевич Рахма́нинов , "Sergey Vasilyevich Rakhmaninov"; ] ; 1 April [O.S. 20 March] 1873 28 March 1943) was a Russian virtuoso pianist, composer, and conductor of the late-Romantic period, some of whose works are among the most popular in the romantic repertoire.
Title: Prince Rostislav (Rachmaninoff)
Passage: Prince Rostislav is a symphonic poem by Sergei Rachmaninoff.  It was composed when he was a student at the Moscow Conservatory, and is one of his earliest surviving compositions for orchestra.  A typical performance of the work lasts from sixteen to twenty minutes.
Sergei Rachmaninoff Prince Rostislav (Rachmaninoff)