Question: Who wrote the "Billboard" Hot 100 number-one hit, featured on Now That's What I Call Music!18?

Context paragraphs:
Now That's What I Call Music! 52 (U.S. series): Now That's What I Call Music!  52 is the 52nd edition of the "Now! " series in the United States.  It was released on October 27, 2014.  It includes the "Billboard" Hot 100 number-one hit, "All About That Bass".

Now That's What I Call Music! 18 (U.S. series): Now That's What I Call Music!  18 is the 18th edition of the Now!  series in the United States and was released on March 15, 2005.  The album peaked at number two on the "Billboard" 200 and has been certified Platinum.  It features one "Billboard" Hot 100 number-one hit, "Drop It Like It's Hot".

It's Gonna Be Me: "It's Gonna Be Me" is a song by American boy band NSYNC.  It was released on June 13, 2000 as the second single in the United States and third in Europe from their second studio album "No Strings Attached".  The song was NSYNC's only "Billboard" Hot 100 number-one hit, making it their highest-charting single.  It topped the chart for two consecutive weeks and has been certified Gold by the RIAA.  The song serves as the opening track of the 2000 compilation album "Now That's What I Call Music!  5".

Now That's What I Call Music! 55 (U.S. series): Now That's What I Call Music!  55 is the 55th edition of the "Now! " series in the United States, and the compilation was released on August 7, 2015.  It features 21 tracks including the "Billboard" Hot 100 number-one hit, "Cheerleader" by OMI.

Now That's What I Call Music! 54 (U.S. series): Now That's What I Call Music!  54 is the 54th edition of the "Now! " series in the United States.  It was released on May 4, 2015.  It features 21 tracks including the "Billboard" Hot 100 number-one hit, "Blank Space" by Taylor Swift.

Now That's What I Call Music! 11 (U.S. series): Now That's What I Call Music!  11 was released on November 19, 2002.  The album is the 11th edition of the (U.S.) Now!  series.  It debuted at its peak of number two on the "Billboard" 200 and has been certified 2x Platinum.  The album features one "Billboard" Hot 100 number-one hit, "Hot In Herre".

Usher discography: American singer Usher has released eight studio albums, nine compilation albums, eight extended plays, and fifty-three singles (including eleven as a featured artist).  His music has been released on the LaFace, Arista, Jive, and RCA record labels.  23 million of his albums were shipped in the United States, and sold over 43 million albums worldwide, leading to a combined 75 million records and making him one of the best selling music artists.  He also has 9 Hot 100 number-one singles (all as a lead) and 18 Hot 100 top-ten singles.  In 1994, Usher released his self-titled debut album in North America, producing three singles that had moderate chart success, and the album sold more than 500,000 copies.  His follow-up 1997 album "My Way" sold 8 million copies, becoming his breakthrough album.  It was certified six-times platinum in the US, and spawned three successful singles, including his first US "Billboard" Hot 100 number-one hit "Nice & Slow".  Usher's success continued in 2001 with his third studio album "8701".  It debuted at number four on the "Billboard" 200.  The album produced two number-one singles—"U Remind Me" and "U Got It Bad".  It has sold more than 4.7 million copies and has been certified four-times platinum in the US.  Its worldwide sales stand at over 8 million.

Now That's What I Call Music! 53 (U.S. series): Now That's What I Call Music!  53 is the 53rd edition of the "Now! " series in the United States.  It was released on February 3, 2015.  It features 21 tracks including the "Billboard" Hot 100 number-one hit "Uptown Funk" by Mark Ronson featuring Bruno Mars.

Now That's What I Call Music! 40 (U.S. series): Now That's What I Call Music!  40 was released on November 8, 2011.  The album is the 40th edition of the "Now! " series in the United States.  To celebrate the release of its 40th disc, two versions were released: the standard edition containing "16 of the hottest tracks from the last few months", including the "Billboard" Hot 100 number-one hit, "Moves Like Jagger", and a two-disc Deluxe Edition set that "includes all the hits in the standard set, as well as the greatest hits from the last several years featured on previous sets."

Drop It Like It's Hot: "Drop It Like It's Hot" is a hit single by American rapper Snoop Dogg featuring American singer and producer Pharrell.  Snoop Dogg performs the chorus and the second and third verses (of three), while Pharrell performs the first verse.  Pharrell's verse includes a line from "Raspy Shit" (a song from his debut album "In My Mind"), which was produced by The Neptunes and contains vocal samples from Laid Back's "White Horse".  Part of "White Horse"'s production is sampled in "Drop It Like It's Hot" as well.

Supporting paragraphs: Now That's What I Call Music! 18 (U.S. series) Drop It Like It's Hot
Answer: Snoop Dogg