Question: The director of a 2015 film based on Austro-Bavarian folklore has collaborated with which screenwriter?

Context paragraphs:
Adam Robitel: Adam Robitel (born May 28, 1978) is an American film director, producer, screenwriter, and actor.  He directed 2014's "The Taking of Deborah Logan", was the co-writer for the 2015 film "", and is also the director for the upcoming 2018 film "".

Freetown (film): Freetown is a 2015 film based on a true story about Mormon missionaries in Liberia seeking to escape the Liberian Civil War to safety in Sierra Leone.

Krampus (film): Krampus is a 2015 American comedy horror film based on the eponymous character from Austro-Bavarian folklore, directed by Michael Dougherty and written by Dougherty, Todd Casey, and Zach Shields.  The film stars Adam Scott, Toni Collette, David Koechner, Allison Tolman, Conchata Ferrell, Emjay Anthony, Stefania LaVie Owen, and Krista Stadler.  It was released in the United States on December 4, 2015, by Universal Pictures.

Corneliu Porumboiu: Corneliu Porumboiu (] ; born 14 September 1975) is a Romanian film director and screenwriter.  His 2006 feature "" won him the Caméra d'Or prize at the Cannes Film Festival.  He is the son of football referee Adrian Porumboiu.  His 2015 film "The Treasure" was screened in the Un Certain Regard section at the 2015 Cannes Film Festival where it won the Prix Un Certain Talent prize.

Michael Dougherty: Michael Dougherty is an American film director, producer, and screenwriter, known for his work with Dan Harris on the scripts for Bryan Singer's films "X2" and "Superman Returns".  He's also known for writing and directing the cult horror film "Trick 'r Treat".  On October 28, 2013, at a special screening, it was announced to the surprise of the audience that a sequel will be produced by Legendary Pictures.  He also directed, co-wrote, and co-produced the horror/comedy "Krampus" (2015).  Dougherty will be co-writing and directing the upcoming sequel "" for a March 22, 2019 release date.

Scot Armstrong: Scot Armstrong is an American screenwriter, director, and producer.  He is credited with writing or co-writing numerous comedy films, including "Old School", "", "Semi-Pro", "Road Trip", and many others.  He is also the writer and director of the 2015 film, "Search Party".  The film will be released in the US in May 2016.  Also in 2016, his TV series, "Dice", premiered on Showtime.

Praboo Ariva: Praboo T. Arivanathan, known as Praboo Ariva, is a Malaysian screenwriter and film director of Indian descent.  He became the youngest film director in Malaysia by directing the 2015 film KID.  Praboo has stated that he intends to pursue film studies in the United States of America.

Jayro Bustamante: Jayro Bustamante is a Guatemalan film director and screenwriter.  He directed the 2015 film "Ixcanul", which was selected as the Guatemalan entry for the Best Foreign Language Film at the 88th Academy Awards.  He was named on the jury for the Best First Feature Award at the 67th Berlin International Film Festival.

Matt Charman: Matt Charman is a British screenwriter, playwright, and producer.  He was nominated for an Academy Award for best original screenplay for his 2015 film "Bridge of Spies", directed by Steven Spielberg and co-written with Joel and Ethan Coen.  Charman started out writing for theatre, making his breakthrough as writer-in-residence at London’s National Theatre, where then director Nicholas Hytner described Charman as having "a priceless nose for a story."  He recently wrote the pilot episode of "Oasis", a sci-fi drama for Amazon Video adapting Michel Faber's "The Book of Strange New Things", and is working on a second movie for Steven Spielberg's Amblin Partners, based on Walter Cronkite’s 1968 visit to Vietnam.

Cesc Gay: Francesc Gay i Puig, better known as Cesc Gay (] ; Barcelona, 1967), is a Spanish film screenwriter and film director.  His 2015 film Truman won Goya Awards for best picture, best director, best actor (Ricardo Darín), best supporting actor (Javier Cámara) and best original screenplay (Cesc Gay and Tomàs Aragay).

Supporting paragraphs: Michael Dougherty Krampus (film)
Answer: Dan Harris