Task: Question Answering
Input (English): Passage: While students at South London's Elliott School in 2005, childhood friends Romy Madley Croft and Oliver Sim formed the xx with Jamie Smith and Baria Qureshi. Croft and Sim played guitar and bass, respectively, and dueted as the band's vocalists, while Smith programmed electronic beats for their songs, and Qureshi doubled as a keyboardist and additional guitarist. During late nights, Croft and Sim either shared lyrics with each other through instant messaging or rehearsed quietly with Smith and Qureshi in their bedrooms so they would not disturb the rest of the household. The xx were greatly influenced by American R&B producers such as The Neptunes and Timbaland, whose minimalist productions incorporated vocal harmonies, clapping percussion, unconventional samples, and pronounced beats. The band covered Aaliyah's "Hot Like Fire" (1997), Womack & Womack's "Teardrops" (1988), and other past R&B hits when they performed live and recorded their demos.After posting the demos on their Myspace page, the xx drew the interest of Young Turks, an imprint label of XL Recordings. They submitted the demos to XL's head office at Ladbroke Grove and were subsequently signed to a recording contract. The group worked with producers such as Diplo and Kwes, to no success before they were introduced to audio engineer Rodaidh McDonald by the xx's manager Caius Pawson, who gave him three CDs of demos titled "Early Demos", "Recorded in Rehearsal Space", and "What Producers Did Wrong". McDonald was impressed by the intimate quality and use of silence on the demos, which both he and the band felt may have challenged other producers who wanted to incorporate their individual tastes: "They'd worked with about four other producers before then that had—and no discredit to them—I guess they'd seen a lot of space to add a kind of stamp on. There was a lot of empty space in the xx's music, even then, in the 'Early Demos'. But we just found that the best stuff was the most sparse.". 
Question: What are the first names of the people who shared lyrics with each other through instant messaging?
Output (English): Oliver.