Does Werther or War and Peace have more acts?
Werther Werther is an opera ("drame lyrique") in four acts by Jules Massenet to a French libretto by Édouard Blau, Paul Milliet and Georges Hartmann (who used the pseudonym Henri Grémont). It is loosely based on the German epistolary novel "The Sorrows of Young Werther" by Johann Wolfgang von Goethe, which was based both on fact and on Goethe's own early life. Earlier examples of operas using the story were made by Kreutzer (1792) and Pucitta (1802).
The Canterville Ghost (Knaifel opera) The Canterville Ghost (also "The Ghost of Canterville", Russian: "Кантервильское привидение" – Kantervíl’skoye privedénie, however usually spelt as "Кентервильское привидение" – Kentervíl’skoye prividénie; French: Le fantôme de Canterville, German: Das Gespenst von Canterville), an opera by the Russian composer Alexander Knaifel (Russian: Кнайфель) in three acts for 18 singers and chamber orchestra, also in an abridged version for two soloists and chamber orchestra.