Which 2017 festival did a Barry Keoghan movie directed by Yorgos Lanthimos was selected to compete in the main competition?
The Killing of a Sacred Deer: The Killing of a Sacred Deer is a 2017 psychological horror-thriller film directed by Yorgos Lanthimos, from a screenplay by Lanthimos and Efthymis Filippou. The Killing of a Sacred Deer:  It was selected to compete for the Palme d'Or in the main competition section at the 2017 Cannes Film Festival.
i don't know