Question: Which opera was written by Wolfgang Amadeus Mozart, Martha or Idomeneo?
Context: Amadeus is a 1984 American period drama film directed by Miloš Forman, adapted by Peter Shaffer from his stage play "Amadeus".  The story, set in Vienna, Austria, during the latter half of the 18th century, is a fictionalized biography of Wolfgang Amadeus Mozart.  Mozart's music is heard extensively in the soundtrack of the movie.  The film follows Italian composer Antonio Salieri at the court of Emperor Joseph II, and his jealous vendetta against his younger rival, Wolfgang Amadeus Mozart. Delores Ziegler (born 4 September 1951) is an American mezzo-soprano who has had an active international performance career since the late 1970s.  A former resident artist at the Cologne Opera, she has performed leading roles with many of the world's best opera houses, including La Scala, the Lyric Opera of Chicago, the Metropolitan Opera, the San Francisco Opera, and the Vienna State Opera.  She is currently a professor of voice at the University of Maryland.  While she has performed a broad repertoire, she is widely admired for her performances in operas by Wolfgang Amadeus Mozart and Richard Strauss; particularly Cherubino in "The Marriage of Figaro", Dorabella in "Così fan tutte", Idamante in "Idomeneo", and Octavian in "Der Rosenkavalier". The Alte Mozart-Ausgabe is the name by which the first complete edition of the music of Wolfgang Amadeus Mozart, is known nowadays, published by Breitkopf & Härtel from January 1877 to December 1883, with supplements published until 1910.  The name "Alte Mozart-Ausgabe" (abbreviated "AMA") is actually a modern invention to distinguish the edition from the second Mozart complete works edition, the "Neue Mozart-Ausgabe"; the publication title of Breitkopf & Härtel's edition was "Wolfgang Amadeus Mozarts Werke.  Kritisch durchgesehene Gesammtausgabe."  (It is therefore sometimes referred to as the ""Mozart Gesammtausgabe"".) Mozart 252 is a 2008 album by Michael Nyman (his 58th release) with the Michael Nyman Band, Hilary Summers, and Andrew Slater, celebrating the 250th anniversary of Wolfgang Amadeus Mozart's birth.  Although "Revisiting the Don," one of only two newly written works on the album, was commissioned and performed in 2006, the album's title is a joke on its lateness as an album, released 252 years after Mozart's birth ("it seemed more appropriate to miss the beat by two years").  The album also includes "In Re Don Giovanni," Nyman's first composition for the band, which is based on the first fifteen bars of "Madamina, il catalogo è questo" from "Don Giovanni", six selections from Peter Greenaway's film, "Drowning by Numbers", in which he was instructed to base the music on the slow movement of Mozart's Sinfonia Concertante K. 364, and two duets and an aria from Nyman's television opera, "Letters, Riddles and Writs", in this recording featuring bass Andrew Slater as Leopold Mozart and contralto Hilary Summers as Wolfgang. Martha, oder Der Markt zu Richmond ("Martha, or The Market at Richmond") is a "romantic comic" opera in four acts by Friedrich von Flotow set to a German libretto by Friedrich Wilhelm Riese and based on a story by Jules-Henri Vernoy de Saint-Georges. Idomeneo, re di Creta ossia Ilia e Idamante (Italian for "Idomeneus, King of Crete, or, Ilia and Idamante"; usually referred to simply as Idomeneo, K. 366) is an Italian language opera seria by Wolfgang Amadeus Mozart.  The libretto was adapted by Giambattista Varesco from a French text by Antoine Danchet, which had been set to music by André Campra as "Idoménée" in 1712.  Mozart and Varesco were commissioned in 1780 by Karl Theodor, Elector of Bavaria for a court carnival.  He probably chose the subject, though it might have been Mozart.  The work premiered on 29 January 1781 at the Cuvilliés Theatre in Munich, Germany. The Neue Mozart-Ausgabe (abbreviated as "NMA"; in English, "New Mozart Edition") is the second complete works edition of the music of Wolfgang Amadeus Mozart.  A longer and more formal title for the edition is "Wolfgang Amadeus Mozart.  Neue Ausgabe sämtlicher Werke." The Oboe Quartet in F major, K. 370/368b, was written by Wolfgang Amadeus Mozart in early 1781.  The quartet is scored for oboe, violin, viola and cello.  In 1780, Mozart was invited to Munich to visit Elector Karl Theodor, who had commissioned the opera "Idomeneo" for a carnival celebration.  While in Munich, Mozart renewed an acquaintance with Friedrich Ramm, a virtuoso oboist in the Munich orchestra.  It was for Ramm that Mozart composed the quartet in order to show off his virtuosity and the improvements that had been made to the oboe at that time.  One way that this piece showed off the instrument was the use of the "high F" above the staff, a note rarely played in any repertoire previously written for the oboe. Franz Xaver Wolfgang Mozart (26 July 1791 – 29 July 1844), also known as Wolfgang Amadeus Mozart, Jr., was the youngest child of six born to Wolfgang Amadeus Mozart and his wife Constanze.  He was the younger of his parents' two surviving children.  He was a composer, pianist, conductor, and teacher from the late classical period whose musical style was of an early Romanticism, heavily influenced by his father's mature style. "This is a mostly complete list of the works of Wolfgang Amadeus Mozart, according to the sixth edition of the Köchel catalogue.  For a selective list of his works, grouped by genre, see List of compositions by Wolfgang Amadeus Mozart".
Answer: Idomeneo