Task: Question Answering
Input (English): Passage: Perry embarked on her second tour, the California Dreams Tour, in support of Teenage Dream from February 2011 to January 2012. The tour grossed $59.5 million globally and won her the award for Best Live Act at the 2011 MTV Europe Music Awards. On September 23, 2011, she performed on the opening day of the 2011 Rock in Rio festival along with Elton John and Rihanna. In September 2010, Perry was scheduled to appear on the 41st-season premiere of Sesame Street. After her scene was uploaded to YouTube, viewers criticized Perry's exposed cleavage. Four days before the scheduled airing, Sesame Workshop announced that the segment would not air on television, but would still be available to watch online. Perry subsequently mocked the controversy on Saturday Night Live, where she was a musical guest and wore an Elmo-themed shirt showing large amounts of cleavage during one skit.In December 2010, Perry played Moe Szyslak's girlfriend in the live-action segment from a Christmas episode of The Simpsons titled "The Fight Before Christmas". In February 2011, she made a guest appearance on the How I Met Your Mother episode "Oh Honey", playing a woman known as Honey. The role won her the People's Choice Award for Favorite TV Guest Star in January 2012. She made her film debut in the 3D family motion picture The Smurfs as Smurfette on July 29, 2011. The film was a financial success worldwide, while critics gave mostly negative reviews. She hosted Saturday Night Live on December 10, 2011, with Robyn as the episode's musical guest. Perry's work on the episode received generally positive reviews from critics, who praised her performance in the episode's digital short featuring her and Andy Samberg. In March 2012, she guest starred as a prison security guard named Rikki on the Raising Hope episode "Single White Female Role Model". On July 5, 2012, Perry's autobiographical documentary Katy Perry: Part of Me was released to theaters through Paramount Pictures. The film received positive reviews and grossed $32.7 million worldwide at the box office.Perry began to venture into business when she endorsed her first fragrance, Purr, in November 2010. Her second fragrance, Meow!, was released in December 2011. Both perfumes were released through Nordstrom department stores. Electronic Arts recruited her to promote their new expansion pack for The Sims 3: Showtime, before releasing a separate stuff pack featuring Perry-inspired furniture, outfits, and hairstyles, titled The Sims 3: Katy Perry's Sweet Treats, in June 2012. The following month, she became the spokesperson and ambassador for Popchips and made an investment in the company. Billboard dubbed her as their "Woman of the Year" for 2012.She married Russell Brand on October 23, 2010, in a traditional Hindu ceremony near the Ranthambhore tiger sanctuary in Rajasthan, India. Brand announced on December 30, 2011, that they were divorcing after 14 months of marriage. Perry later stated that conflicting career schedules and his desire to have children before she was ready led to the end of their marriage and that he never spoke to her again after sending a text message that he was divorcing her, while Brand asserted that he divorced her due to her commercial success and reluctance to engage in activism. She was initially distraught over their divorce, and said that she contemplated suicide. After the marriage ended in 2012, Perry began a relationship with singer John Mayer that August. 
Question: What is the first name of the person who performed on the opening day of the 2011 Rock in Rio festival along with Elton John and Rihanna?
Output (English): Katy.