Question: What is the stage name for actor who co-stared the 2016 film "Train to Busan" with Jung Yu-mi and Ma Dong-seok?

Related documents: [0]  [DOC] Train to Busan () is a 2016 South Korean zombie apocalypse action thriller film directed by Yeon Sang-ho and starring Gong Yoo, Jung Yu-mi, and Ma Dong-seok. The film takes place on a train to Busan, as a zombie apocalypse suddenly breaks in the country and compromises the safety of the passengers. [END] 
[1]  [DOC] Gong Ji-chul (; born July 10, 1979), better known by his stage name Gong Yoo (), is a South Korean actor. He is best known for his roles in television dramas "The 1st Shop of Coffee Prince" (2007) and "" (2016-2017), and the films "Silenced" (2011), "The Age of Shadows" (2016), and "Train to Busan" (2016). [END]  
Answer: Gong Yoo
Gong Yoo