Problem: Background: Federico Fellini, Cavaliere di Gran Croce OMRI (Italian: [fede'ri:ko fel'li:ni]; 20 January 1920 - 31 October 1993) was an Italian film director and screenwriter. Known for his distinct style that blends fantasy and baroque images with earthiness, he is recognized as one of the greatest and most influential filmmakers of all time. His films have ranked, in polls such as Cahiers du cinema and Sight & Sound, as some of the greatest films of all time. Sight & Sound lists his 1963 film 8 1/2  as the 10th-greatest film of all time.
Context: Retained on business in Rimini, Urbano sent wife and family to Rome in 1940 to share an apartment with his son. Fellini and Ruggero Maccari, also on the staff of Marc'Aurelio, began writing radio sketches and gags for films.  Not yet twenty and with Fabrizi's help, Fellini obtained his first screen credit as a comedy writer on Mario Mattoli's Il pirata sono io (The Pirate's Dream). Progressing rapidly to numerous collaborations on films at Cinecitta, his circle of professional acquaintances widened to include novelist Vitaliano Brancati and scriptwriter Piero Tellini. In the wake of Mussolini's declaration of war against France and England on 10 June 1940, Fellini discovered Kafka's The Metamorphosis, Gogol, John Steinbeck and William Faulkner along with French films by Marcel Carne, Rene Clair, and Julien Duvivier. In 1941 he published Il mio amico Pasqualino, a 74-page booklet in ten chapters describing the absurd adventures of Pasqualino, an alter ego.  Writing for radio while attempting to avoid the draft, Fellini met his future wife Giulietta Masina in a studio office at the Italian public radio broadcaster EIAR in the autumn of 1942. Well-paid as the voice of Pallina in Fellini's radio serial, Cico and Pallina, Masina was also well known for her musical-comedy broadcasts which cheered an audience depressed by the war. In November 1942, Fellini was sent to Libya, occupied by Fascist Italy, to work on the screenplay of I cavalieri del deserto (Knights of the Desert, 1942), directed by Osvaldo Valenti and Gino Talamo. Fellini welcomed the assignment as it allowed him "to secure another extension on his draft order". Responsible for emergency re-writing, he also directed the film's first scenes. When Tripoli fell under siege by British forces, he and his colleagues made a narrow escape by boarding a German military plane flying to Sicily. His African adventure, later published in Marc'Aurelio as "The First Flight", marked "the emergence of a new Fellini, no longer just a screenwriter, working and sketching at his desk, but a filmmaker out in the field".  The apolitical Fellini was finally freed of the draft when an Allied air raid over Bologna destroyed his medical records. Fellini and Giulietta hid in her aunt's apartment until Mussolini's fall on 25 July 1943. After dating for nine months, the couple were married on 30 October 1943. Several months later, Masina fell down the stairs and suffered a miscarriage. She gave birth to a son, Pierfederico, on 22 March 1945, but the child died of encephalitis a month later on 24 April 1945. The tragedy had enduring emotional and artistic repercussions.
Question: How many screen plays has he done?
Answer: Several

Problem: Background: Stephen Arthur Stills (born January 3, 1945) is an American singer, songwriter, and multi-instrumentalist best known for his work with Buffalo Springfield and Crosby, Stills, Nash & Young. Beginning his professional career with Buffalo Springfield, he composed one of their few hits "For What It's Worth," which became one of the most recognizable songs of the 1960s. Other notable songs he contributed to the band were "Sit Down, I Think I Love You
Context: Stills, Furay, and Young reunited in Los Angeles and formed the core of Buffalo Springfield. Legend has it that Stills and Furay recognized Young's converted hearse on the streets of LA and flagged him down, a meeting described in a recent solo track "Round the Bend." The band would release three albums: Buffalo Springfield, Buffalo Springfield Again, and Last Time Around, and enjoy only one hit single, the Stills-penned "For What It's Worth" before disbanding. A Stills song from their debut album, "Sit Down, I Think I Love You," was a minor hit for the Mojo Men in 1967.  During the disintegration of Buffalo Springfield, Stills played on the Super Session album with Al Kooper and joined up with David Crosby, who had recently been ejected from the Byrds in the autumn of 1967. At a party in Laurel Canyon, Crosby was introduced to Graham Nash by a mutual friend, Cass Elliot (formerly of the Mamas and the Papas), and Nash found himself soon joining in singing with Crosby and Stills. Renditions of the latter's "You Don't Have to Cry," led to the formation of Crosby, Stills & Nash. Several of Stills's songs, including "Suite: Judy Blue Eyes" and "You Don't Have To Cry" on the debut album were inspired by his on-again-off-again relationship with singer Judy Collins. In a 1971 interview in Rolling Stone the interviewer noted, "so many of your songs seem to be about Judy Collins." Stills replied, "Well, there are three things men can do with women: love them, suffer for them, or turn them into literature. I've had my share of success and failure at all three."  The cover photo pictured on the debut was taken on the back porch of a house in West Hollywood, which was torn down the next day. Wanting to be able to tour and needing additional musicians, the band invited Neil Young to join them for their subsequent tour and second album to make the group the quartet Crosby Stills Nash & Young.  Having played at the Monterey Pop Festival with Buffalo Springfield, and both Woodstock and Altamont with CSNY, Stills performed at all three of the iconic U.S. rock festivals of the 1960s.
Question: Who did Stills work with
Answer:
Stills, Furay, and Young reunited in Los Angeles and formed the core of Buffalo Springfield.