Question: What country does Perry have the most number ones?
About the article "Wide Awake (Katy Perry song)", section "Commercial performance".

Candidate passages:
  "Teenage Dream" by Katy Perry holds the record for most digital number-ones from one album, with five.
"California Gurls," "Teenage Dream," "Firework," "E.T."
and "Last Friday Night (T.G.I.F.)"
have all topped the chart.  
  Rihanna (12)  Mariah Carey(11)   Usher and Katy Perry (7)  Ludacris, Kanye West (6)  50 Cent, Beyoncé, Boyz II Men and Bruno Mars (5) Artist with the most number ones BDS-based chart's December 1990 inception. 
The discography of Brad Paisley, an American country music singer, consists of nine studio albums, one Christmas album, two compilation albums, and twenty-eight singles.
All of Paisley's singles have hit the Top Twenty of the "Billboard" Hot Country Songs charts, with all but three reaching the Top Ten.
He has eighteen Number Ones---including a streak of ten consecutive, starting with the 2005–06 Dolly Parton duet "When I Get Where I'm Going".
When "Waitin' on a Woman", reached #1 in late 2008, Paisley set a new record for the most consecutive Number Ones (8) by any country artist since the inception of Nielsen SoundScan in 1990.
This streak lasted until mid-2009's #2 single "Welcome to the Future".
He held the record until 2014, when Blake Shelton recorded his 11th consecutive number one single with Doin' What She Likes.  
  Katy Perry - 5 - "California Gurls", "Teenage Dream", "Firework", "E.T.
", "Last Friday Night (T.G.I.F.)"
Commercial performance.
North America.
On the "Billboard" Hot 100, the song debuted at number eighty-five on the week-ending August 24, 2013 due to radio airplay.
The following week, during its first week on sale, "Roar" sold 557,000 digital copies, thus earning Perry the highest first-week sales numbers of 2013 and also her biggest digital song sales week ever, breaking her previous record held by "Firework", which sold 509,000 digital copies for the week ending January 8, 2011.
The song soared eighty-three positions to number two in its second week, kept from the top spot by only Robin Thicke's "Blurred Lines", while becoming Perry's twelfth top-ten hit single in the United States, and her ninth consecutive single to peak within the top three on the Hot 100.
After another week at number two, "Roar" reached number one for the chart dated September 14, 2013, becoming Perry's eighth number one on the Hot 100 and her ninth digital number-one single, after selling 448,000 copies.
"Roar" spent a total two weeks at number one before it was surpassed by Miley Cyrus' "Wrecking Ball".
On its seventh frame, the song moved 2-1 (peak audience impressions of 159 million) and became Perry's sixth number one on the Hot 100 Airplay, as well as becoming the singer's fastest climbing to the top position.
"Roar" also reached number one on both the US Pop Songs and Adult Pop Songs.
The number-one position on the "Pop Songs" chart gave Perry her tenth number one, tying her with Rihanna for the most number ones on the airplay-based chart.
The number-one position on the "Adult Pop Songs" chart also gave Perry multiple milestones; it became her eighth chart topper, tying her with Maroon 5 and P!nk as the act with the most number-ones there.
It also made the fastest ascension to the top spot; a record previously held by Perry's own single "California Gurls" (2010).
It also set airplay records in both of the charts, by becoming the most weekly-played song in history, with 16,065 and 5,309 plays per week, respectively.
The song has also reached the top spot on both the Adult contemporary chart and Hot Dance Club Songs.
In addition to this, the track also reached number one on both the On Demand and Streaming charts, with a weekly peak of 2.1 million and 12 million, respectively.
"Roar" surpassed digital sales of four million in its seventeenth week, faster than any other song in digital history.
Its sales reached 4.41 million by the end of 2013, becoming the sixth best-seller of the year.
Perry has seven of her songs with sales more than four million, the most for any artist.
By February 2014, "Roar" had surpassed five million sales, and was Perry's fifth song to reach that level.
Perry is the only artist to have five quintuple million sellers.
On August 31, 2013, "Roar" debuted at number one on the Canadian Hot 100 on the strength of digital downloads.
In doing so, it became only the eleventh song to debut at the peak position on the chart, and it also became Perry's third number-one debut, making her the artist with the most number one debuts on the chart.
It also became Perry's ninth Canadian number one, breaking the tie she shared with Rihanna for the most chart toppers in the country.
It has so far spent five non-consecutive weeks atop the chart.
"Roar" was also in the top of the Canadian Digital Chart for three non-consecutive weeks; there, it was Perry's sixth number-one single.
In Mexico, it reached number one on the Monitor Latino English-language airplay chart.