Seventeen is a South Korean boy group formed by Pledis Entertainment in 2015. The group consists of 13 members: S.Coups, Jeonghan, Joshua, Jun, Hoshi, Wonwoo, Woozi, DK, Mingyu, The8, Seungkwan, Vernon, and Dino. Seventeen is considered a "self-producing" idol group, with members actively involved in songwriting, music production, and choreography. The group is divided into three sub-units: Hip-Hop Team, Vocal Team, and Performance Team, each specializing in a different area. Woozi is the leader of the vocal team and the group's main producer, having contributed as a writer or composer to over 80% of the group's discography. Hoshi has co-choreographed most of Seventeen's title tracks, and other members of the performance team also create choreography for their sub-unit's songs. Seventeen debuted on May 26, 2015, with the extended play (EP) "17 Carat". This EP was the longest-charting K-pop album of the year in the US and the only rookie album on Billboard's "10 Best K-Pop Albums of 2015" list.