Definition: In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.
Input: Question: How many years after Ivan IV of Russia came to power did he conquer the Dorpat area? Passage 1:Born in Muzzana del Turgnano, Frossi began his career as a professional footballer with Udinese, and, after a long stay in Serie B (with Padova, Bari, and L’Aquila), he was acquired by Ambrosiana Inter, where he made his debut on 21 June 1936, in Mitropa Cup. After that, Frossi was called up for the 1936 Summer Olympics by Vittorio Pozzo, the coach of the Italian national side, leading the team to the victory of the tournament with his prolific performances. In the following years, Frossi played with Inter from 1936 until 1942, winning the “Scudetto” or league championship, twice in 1938 and 1940, as well as the Coppa Italia in 1939. He scored 49 goals in 147 matches with Inter, 40 of which came in the league, in 125 appearances. During World War II, he later also played with Pro Patria between 1942 and 1943, and Como in 1945, before retiring.
 Passage 2:Lewis was born in Bermuda, the youngest of the three children – all boys – of Major Leonard Carey Lewis (1880–1952) and his wife, Katherine Barbara, née Sutton (1884–1965). There was a military tradition on both sides of the family, which the young Lewis did not follow: his musical talent became clear from his early years and he was sent to Salisbury Cathedral choir school, and at the age of eight he became a chorister at St George's Chapel, Windsor. At the age of 13 Lewis attended the Royal Academy of Music (RAM), London, studying composition with William Alwyn. He won a scholarship to Wellington College, from where, in 1932, he went to Peterhouse, Cambridge. There, according to The Times, he was "one of the most brilliant of his generation to have come under the influence of E.J.Dent". A scholarship enabled him to spend some months studying in Paris with Nadia Boulanger in 1934. He graduated the following year as BA and MusB.
 Passage 3:With the Treaty of Pozvol, concluded in 1557, the Livonian Confederation had turned to Poland-Lithuania for protection, triggering Ivan IV of Russia's intervention in what was to become the Livonian War. In 1558, Ivan IV had conquered the Dorpat (Tartu) area, annihilating the Bishopric of Dorpat. With the Treaty of Vilnius of 31 August 1559, Gotthard von Kettler, Grand Master of the Livonian Order, had put the order's lands under protection of Polish king and Grand Duke of Lithuania, Sigismund II Augustus. The order ceded about one seventh of its territory, allowed Sigismund to garrison its most important castles, and agreed to share with him any conquests made from Ivan IV. The alliance was intended to neutralize the imminent threat of annexation of the order's lands by Russia, yet despite earning military support from Polish-Lithuanian chancellor Mikołaj "the Black" Radziwiłł, Kettler was defeated in Ergeme (Ermes, 1560) and unable to prevent the occupation of most of Livonia by Russian forces. After the treaty, the disintegrating order agreed to secularization if necessary, and since Sigismund was reluctant to support it militarily, continued its search for a protector at the courts of Denmark-Norway and the Holy Roman Emperor.

Output:
3