Task: Question Answering
Input (English): Passage: Pyotr Ilyich Tchaikovsky (English:  chy-KOF-skee; Russian: Пётр Ильи́ч Чайко́вский, tr. Pyótr Ilʹyích Chaykóvskiy, IPA: [pʲɵtr ɪlʲˈjitɕ tɕɪjˈkofskʲɪj] (listen); 7 May 1840 [O.S. 25 April] – 6 November [O.S. 25 October] 1893), was a Russian composer of the romantic period, whose works are among the most popular music in the classical repertoire. He was the first Russian composer whose music made a lasting impression internationally, bolstered by his appearances as a guest conductor in Europe and the United States. He was honored in 1884 by Emperor Alexander III, and awarded a lifetime pension.
Although musically precocious, Tchaikovsky was educated for a career as a civil servant. There was scant opportunity for a musical career in Russia at that time and no system of public music education. When an opportunity for such an education arose, he entered the nascent Saint Petersburg Conservatory, from which he graduated in 1865. The formal Western-oriented teaching he received there set him apart from composers of the contemporary nationalist movement embodied by the Russian composers of The Five, with whom his professional relationship was mixed. Tchaikovsky's training set him on a path to reconcile what he had learned with the native musical practices to which he had been exposed from childhood. From this reconciliation he forged a personal but unmistakably Russian style—a task that did not prove easy. The principles that governed melody, harmony and other fundamentals of Russian music ran completely counter to those that governed Western European music; this seemed to defeat the potential for using Russian music in large-scale Western composition or for forming a composite style, and it caused personal antipathies that dented Tchaikovsky's self-confidence. Russian culture exhibited a split personality, with its native and adopted elements having drifted apart increasingly since the time of Peter the Great. This resulted in uncertainty among the intelligentsia about the country's national identity—an ambiguity mirrored in Tchaikovsky's career.
Despite his many popular successes, Tchaikovsky's life was punctuated by personal crises and depression. Contributory factors included his early separation from his mother for boarding school followed by his mother's early death, the death of his close friend and colleague Nikolai Rubinstein,  and the collapse of the one enduring relationship of his adult life, which was his 13-year association with the wealthy widow Nadezhda von Meck who was his patron even though they never actually met each other. His homosexuality, which he kept private, has traditionally also been considered a major factor, though some musicologists now downplay its importance. Tchaikovsky's sudden death at the age of 53 is generally ascribed to cholera; there is an ongoing debate as to whether cholera was indeed the cause of death, and whether his death was accidental or self-inflicted. 
Question: What is the last name of the person whose early separation from his mother for boarding school was followed by his mother's early death?
Output (English): Tchaikovsky.