Task: Question Answering
Input (English): Passage: While Perry's music incorporates pop, rock, and disco, Katy Hudson contains gospel. Her subsequent releases, One of the Boys and Teenage Dream, involve themes of sex and love. One of the Boys is a pop rock record, while Teenage Dream features disco influences. Perry's fourth album, Prism, is significantly influenced by dance and pop music. Lyrically, the album addresses relationships, self-reflection, and everyday life. The singer's fifth studio effort Witness is an electropop album that she described as a "360-degree liberation" record, with themes including political liberation, sexual liberation, and liberation from negativity. Many of her songs, particularly on Teenage Dream, reflect on love between teenagers; W described the album's sexual innuendos as "irresistible hook-laden melodies". Self-empowerment is a common theme in Perry's music.Perry describes herself as a "singer-songwriter masquerading as a pop star" and maintains that honest songwriting is very important to her. She told Marie Claire: "I feel like my secret magic trick that separates me from a lot of my peers is the bravery to be vulnerable and truthful and honest. I think you become more relatable when you're vulnerable." Kristen Wiig commented that "as easy, breezy, and infectious as Perry's songs can be, beneath the surface lurks a sea of mixed emotions, jumbled motives, and contradictory impulses complicated enough to fill a Carole King record." According to Greg Kot of the Chicago Tribune, "being taken seriously may be Perry's greatest challenge yet." The New York Times labeled her "the most potent pop star of the day – her hits are relatable with just a hint of experimentation". Randall Roberts of the Los Angeles Times criticized her use of idioms and metaphors in her lyrics and for frequent "clichés". Throughout her career, Perry has co-written songs recorded by other artists, including Selena Gomez & the Scene, Jessie James, Kelly Clarkson, Lesley Roy, Britney Spears, Iggy Azalea, Ariana Grande, and Nicki Minaj. 
Question: What was the name of Perry's fifth album?
Output (English): Witness.