Hong Seok-Hyun (R), chairman of South Korea's Baduk Association, awards an honorary "ninth dan" professional ranking for AlphaGo to Google co-founder Sergey Brin during a press conference after South Korean professional Go player Lee Sedol finished the final match of the Google DeepMind Challenge Match against Google's artificial intelligence program, AlphaGo, in Seoul, South Korea, March 15, 2016. (Photo/Xinhua)
