Complex sentence: From April 1 to 9, a contest sponsored by Samsung enabled fans to enter and win tickets to attend the showcase with their respective subgroups, EXO-K promoted in Korea while EXO-M promoted in China.
Split into simpler sentences: From April 1 to 9, a contest sponsored by Samsung enabled fans to enter and win tickets to attend the showcase. They promoted into their respective subgroups, EXO-K promoted in Korea while EXO-M promoted in China.