Complex sentence: However, nearly 16 years after their last performance, the band held a reunion concert on April 14,2016 at the Seoul World Cup Stadium (also known as Sangam Stadium), which was organized by Infinite Challenge, a popular South Korean television program.
Split into simpler sentences: However, nearly 16 years after their last performance, the group held a reunion concert on April 14,2016 at the Seoul World Cup Stadium (also known as Sangam Stadium). The idea for their reunion concert was initiated and organized by Infinite Challenge, a popular South Korean television program.