SEOUL, South Korea (AP) — Chang Ung, a former North Korean member of the International Olympic Committee who once led sports exchanges with rival South Korea including joint marches of their athletes at the Olympics, has died, the IOC announced Wednesday. He was 87. The IOC said on its website that it had learned with “extreme sadness” of Chang’s death on Sunday. It said the Olympic flag will be flown at half-mast for three days at Olympic House in Lausanne, Switzerland in a show of respect.