A Life for the Tsar is a  Russian libretto with four acts, Tosca an Italian libretto has how many acts?
Tosca 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.
Cinderella (Fitinhof-Schell) Cinderella (ru. «Золушка», "Zolushka") (fr. "Cendrillon") is a "ballet-féerie" in three acts, with the choreographyof Enrico Cecchetti (Acts I and III) and Lev Ivanov (Act II) supervised by Marius Petipa. Music is by Baron Boris Fitinhoff-Schell; the libretto is by Lidia Pashkova (ru: Лидия Александровна Пашкова) and Ivan Vsevolozhsky. It was first presented by the Imperial Ballet on 17 December [O.S. 5 December] 1893 at the Imperial Mariinsky Theatre in St. Petersburg, Russian Empire.