A year after the release of EX'ACT/Lotto, K-pop nine-piece EXO returned with their fourth full-length, The War (S.M. Entertainment/Genie Music). The nine-track collection includes the hit single "Ko Ko Bop" on both Korean- and Mandarin-language versions of the album. Upon release, The War topped the Korean and Billboard World Albums charts, climbing into the Top 90 on the Billboard 200.