Question: The year that the film "Paulina" won the Cannes Film Festival Nespresso Grand Prize, who were the Presidents of the Jury for the main competition?
Context: László Nemes (born Nemes Jeles László; ] ; 18 February 1977) is a Hungarian film director and screenwriter.  His 2015 debut feature film, "Son of Saul," was screened in the main competition at the 2015 Cannes Film Festival, where it won the Grand Prix.  He is the first Hungarian director whose film has won a Golden Globe for Best Foreign Language Film.  "Son of Saul" is the second Hungarian film to win the Academy Award for Best Foreign Language Film.  In 2016, Nemes was a member of the main competition jury of the 2016 Cannes Film Festival. The Prize of the Ecumenical Jury (French: "Prix du Jury Œcuménique" ) is an independent film award for feature films at major international film festivals since 1973.  The award was created by Christian film makers, film critics and other film professionals.  The objective of the award is to "honour works of artistic quality which witnesses to the power of film to reveal the mysterious depths of human beings through what concerns them, their hurts and failings as well as their hopes."  The ecumenical jury can be composed out of 8, 6, 5, 4 or 3 members, who are nominated by SIGNIS for the Catholics and Interfilm for the Protestants.  SIGNIS and Interfilm appoint ecumenical juries at various international film festivals, including Cannes Film Festival (where The Ecumenical Jury (French: "Jury Œcuménique" ) is one of three juries at the film festival, along with the official jury and the FIPRESCI jury), Berlin International Film Festival, Locarno International Film Festival, Montreal World Film Festival and the Karlovy Vary International Film Festival. Mimosas (original title: Mimosas) is a 2016 drama film directed and co-written by Oliver Laxe, described by Laxe as 'a Religious Western'.  The film is a co-production between Spain, Morocco, France and Qatar.  It was screened in the International Critics' Week section at the 2016 Cannes Film Festival where it won the Nespresso Grand Prize. Paulina (Spanish: La patota ) is a 2015 internationally co-produced thriller film directed by Santiago Mitre.  It was screened in the International Critics' Week section at the 2015 Cannes Film Festival where it won the Nespresso Grand Prize and the FIPRESCI Prize.  It is inspired by the 1960 film "La patota". Martina Gusmán (born 28 October 1978) is an Argentine actress and film producer.  She starred in the 2010 film "Carancho", which was entered into the Un Certain Regard section at the 2010 Cannes Film Festival.  In 2011 she was a member of the jury for the main competition at the 2011 Cannes Film Festival. The 63rd Cannes Film Festival was held from 12 to 23 May 2010, in Cannes, France.  The Cannes Film Festival, hailed as being one of the most recognized and prestigious film festivals worldwide, was founded in 1946.  It consists of having films screened in and out of competition during the festival; films screened in competition compete for the Palme d'Or award.  The award in 2010 was won by "Uncle Boonmee Who Can Recall His Past Lives", a Thai film directed by Apichatpong Weerasethakul.  This was determined by the festival's jury members who reviewed films screened in competition.  American film director Tim Burton was the president of the jury for the international competition, and other members of the jury for that competition included actors, screenwriters and composers, such as Kate Beckinsale, Emmanuel Carrère, Benicio del Toro, and Alexandre Desplat.  Other categories for films screened in competition that have their own separate juries for other awards are for Short Films and the Un Certain Regard category. Ahmed El Maanouni is a screenwriter, film director, cinematographer, actor and producer born in Casablanca.  His films include "Alyam Alyam" (1978), the first Moroccan film to be selected in Cannes Film Festival and winner of the Grand Prize at the Mannheim film festival.  He caught international attention when his film "Trances" was honored and presented by Martin Scorsese at the 2007 Cannes Film Festival to inaugurate the World Cinema Foundation.  His film "Les Coeurs brûlés" (2007) won the Grand Prize at the National Film festival and was awarded many international prizes.  His documentary films consistently interrogate colonial history and its impact on Moroccan memory. Makala is a 2017 French documentary film directed by Emmanuel Gras.  It was screened in the International Critics' Week section at the 2017 Cannes Film Festival.  At Cannes, it won the Nespresso Grand Prize. The 68th Cannes Film Festival was held from 13 to 24 May 2015.  Joel and Ethan Coen were the Presidents of the Jury for the main competition.  It was the first time that two people chaired the jury.  Since the Coen brothers each received a separate vote, they were joined by seven other jurors to form the customary nine-juror panel.  French actor Lambert Wilson was the host for the opening and closing ceremonies. The 64th Cannes Film Festival was held from 11 to 22 May 2011.  American actor Robert De Niro served as the president of the jury for the main competition and French filmmaker Michel Gondry headed the jury for the short film competition.  South Korean film director Bong Joon-ho was the head of the jury for the Caméra d'Or prize, which is awarded to the best first-time filmmaker.
Answer: Joel and Ethan Coen