South Korean protesters burn a North Korean and Unification flag during a rally against a visit of North Korean Hyon Song Wol, head of a North Korean art troupe, in front of Seoul Railway Station in Seoul, South Korea, Monday, Jan. 22, 2018. The head of a hugely popular North Korean girl band crossed the heavily fortified border into South Korea on Sunday as part of an official delegation, triggering a media frenzy as she checked potential venues for performances during next month's Winter Olympics. (AP Photo/Ahn Young-joon)