Question: A Life for the Tsar is a  Russian libretto with four acts, Tosca an Italian libretto has how many acts?
Related documents: [0]  [DOC] Tosca (] ) is an opera in three acts by Giacomo Puccini to an Italian libretto by Luigi Illica and Giuseppe Giacosa. It premiered at the Teatro Costanzi in Rome on 14 January 1900. The work, based on Victorien Sardou's 1887 French-language dramatic play, "La Tosca", is a melodramatic piece set in Rome in June 1800, with the Kingdom of Naples's control of Rome threatened by Napoleon's invasion of Italy. It contains depictions of torture, murder and suicide, as well as some of Puccini's best-known lyrical arias. [END] 
[1]  [DOC] A Life for the Tsar (Russian: Жизнь за царя , "Zhizn' za tsarya"), as it is known in English, although in Soviet times its name was "Ivan Susanin" (Russian: Иван Сусанин ) is a "patriotic-heroic tragic opera" in four acts with an epilogue by Mikhail Glinka. The original Russian libretto, based on historical events, was written by Nestor Kukolnik, Egor Fyodorovich (von) Rozen, Vladimir Sollogub and Vasily Zhukovsky. It premiered on 27 November 1836 OS (9 December NS) at the Bolshoi Kamenny Theatre in St. Petersburg. The historical basis of the plot involves Ivan Susanin, a patriotic hero of the early 17th century who gave his life in the expulsion of the invading Polish army for the newly elected Tsar Mikhail, the first of the Romanov dynasty, elected in 1613. [END] 
Answer: 
three acts
three acts