Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

[EX Q]: Context: FreeBSD is a free Unix-like operating system descended from Research Unix via the Berkeley Software Distribution (BSD). 
 Question: The FreeBSD is based upon what?
[EX A]: berkeley software distribution

[EX Q]: Context: The Godfather Part II presents two parallel storylines. One involves Mafia chief Michael Corleone in 1958/1959 after the events of the first movie; the other is a series of flashbacks following his father, Vito Corleone from 1917 to 1925, from his youth in Sicily (1901) to the founding of the Corleone family in New York.The film begins in 1901, in the town of Corleone, Sicily, at the funeral of young Vito's father, Antonio Andolini, who has been murdered for an insult to the local Mafia lord, Don Ciccio. During the procession, Vito's older brother is murdered because he swore revenge on the Don. Vito's mother goes to Ciccio to beg for mercy, but he refuses, knowing that nine-year-old Vito will seek revenge later in life. The mother takes Ciccio hostage at knifepoint, allowing her son to escape, and Ciccio's men kill her. They search the town for the boy, but he is aided in his escape by the townspeople. Vito finds his way by ship to New York, and at Ellis Island an immigration agent chooses Vito's hometown of Corleone as his surname, and he is registered as "Vito Corleone".In 1958 in a scene similar to the opening of the first film, Michael Corleone (Al Pacino), Godfather of the Corleone family, deals with various business and family problems during an elaborate party at his Lake Tahoe, Nevada compound to celebrate his son's First Communion. In his office, Michael meets with corrupt Nevada Senator Pat Geary (G. D. Spradlin) to discuss the price of the gaming licenses for the hotel/casinos the Family is buying. Geary, who has obvious contempt for Michael and other Italian businessmen who are moving into his state to take advantage of gambling opportunities, promises to make Michael's acquisition of his gaming license a difficult process. Michael ends his conversation with Geary when he refuses to pay the outrageous fee Geary demands, telling the senator he'll get nothing.Michael also deals with his self-indulgent younger sister Connie (Talia Shire), who, although recently divorced from her second husband, is planning to marry a man named Merl Johnson (Troy Donahue) with no obvious means of support and of whom Michael disapproves. He also talks with Johnny Ola (Dominic Chianese), the right hand man of Jewish gangster Hyman Roth (Lee Strasberg), who is supporting Michael's move into the gambling industry. Belatedly, Michael deals with Frank "Five Angels" Pentangeli (Michael V. Gazzo), a business associate who took over Corleone caporegime Peter Clemenza's territory in New York City after his death, and now has problems with the Rosato Brothers, who are backed by Roth. Pentangeli leaves abruptly, after telling Michael "your father did business with Hyman Roth, your father respected Hyman Roth, but your father never trusted Hyman Roth."Later that night, Michael barely escapes an assassination attempt when his wife Kay (Diane Keaton) notices the bedroom window drapes are inexplicably open, which allows two unseen hitmen to spray the bedroom with bullets. The two hitman are found dead having been killed by a "mole" within the compound. Afterwards, Michael tells his lawyer and associate Tom Hagen (Robert Duvall) that the hit was made with the help of someone close, and that he must leave, entrusting all his power to Hagen to protect his family.Flashback: In 1917 New York City, the adult Vito Corleone (Robert De Niro) works in a grocery store in the Lower East side with his friend Genco Abbandando. The neighborhood is controlled by a member of the "The Black Hand," Don Fanucci (Gastone Moschin), who extorts protection payments from local businesses. One night, Vito's neighbor Clemenza (Bruno Kirby) asks him to hide a stash of guns for him, and later, to repay the favor, takes him to a fancy apartment where they commit their first felony together, stealing an elegant rug.The film flash-forwards to Michael's time. Michael meets with poushal Hyman Roth in Miami, Florida who tells Michael that he believes Frank Pentangeli was responsible for the assassination attempt, and that Pentangeli will pay for it 
 Question: Who visits Sicily for the first time since emigrating?
[EX A]: vito

[EX Q]: Context: Castigliano's method, named for Carlo Alberto Castigliano, is a method for determining the displacements of a linear-elastic system based on the partial derivatives of the energy. 
 Question: Who was the original discoverer of Castigliano's method?
[EX A]:
carlo alberto castigliano