Question: Which film, The Front Line or Secret Reunion, one of the highest grossing Korean films of 2010?

Context paragraphs:
Jang Hoon: Jang Hoon (born May 4, 1975) is a South Korean film director.  He directed the films "Rough Cut" (2008), "Secret Reunion" (2010), "The Front Line" (2011), and "A Taxi Driver" (2017).

Lee Joon-ik: Lee Joon-ik (born September 21, 1959) is an award winning South Korean film director and producer.  He is best known for directing and producing "King and the Clown" (2005), one of the highest grossing Korean films of all time.  Other notable films include "Once Upon a Time in a Battlefield" (2003), "Radio Star" (2006), and "Hope" (2013).

Secret Reunion: Secret Reunion (; lit.  "Sworn Brothers" or "Blood Brothers") is a 2010 South Korean spy thriller film directed by Jang Hoon, and one of the highest grossing Korean films of 2010.

Ryu Seung-ryong: Ryu Seung-ryong (born November 29, 1970) is a South Korean actor.  Ryu began his acting career in theater, subsequently becoming one of the most versatile supporting actors in Korean film and television.  In 2013, he headlined "Miracle in Cell No. 7", which became (at the time) the third highest grossing Korean film of all time.

Singles (2003 film): Singles is a 2003 South Korean romantic comedy film starring Jang Jin-young, Uhm Jung-hwa, Lee Beom-soo, and Kim Joo-hyuk.  It is based on the novel "Christmas at Twenty-nine" by Japanese writer Kamato Toshio.  The film was one of the highest grossing Korean films of all time earning 2,203,164 admissions nationwide.

List of North Korean films: This is a list of North Korean films and film series from September 1948 to present.  Films, and film parts or halves with names, that are part of film series or multi-part films are not included separately to keep the list shorter and more readable.  For South Korean films from September 1948 see list of South Korean films.  Earlier Korean films made during Japanese rule are in the list of Korean films of 1919–1948.  For an alphabetical list of Korean language films, see list of Korean language films.

Fighter in the Wind: Fighter in the Wind (Korean: 바람의 파이터 ) is a 2004 South Korean film.  It is based on the Japanese book "Karate Baka Ichidai" which is a fictionalized account of karate competitor Choi Yeung-Eui (최영의, 崔永宜) who went to Japan after World War II to become a fighter pilot but found a very different path instead.  He changed his name to Masutatsu Oyama (大山倍達) and went across the country, defeating martial artists one after another.  This film concentrates on the period when he is still young, and developing his famous karate style, Kyokushin.  The film was the seventh highest grossing Korean film of 2004 with 2,346,446 admissions sold nationwide.

Kim Young-tak: Kim Young-tak (born 1976) is a South Korean film director and screenwriter.  Kim wrote and directed the comedy film "Hello Ghost" (2010).  The comedy was a local hit - the 9th highest grossing Korean film in 2010, and won him the Best New Director (Film) at the 47th Baeksang Arts Awards in 2011.

Kang Hyeong-cheol: Kang Hyeong-cheol is a South Korean film director and screenwriter.  His first two films "Scandal Makers" (2008) and "Sunny" (2011) have been the highest grossing Korean films of their respective years, and are both among the highest grossing Korean films of all time.  Kang won Best Director at the 48th Grand Bell Awards in 2011.

The Front Line (2011 film): The Front Line (; also known as "Battle of Highlands") is a 2011 South Korean war film directed by Jang Hoon, set during the 1953 ceasefire of the Korean War.  This is the third film by director Jang Hoon, after completing "Secret Reunion" and "Rough Cut".  It was selected as South Korea's submission to the 84th Academy Awards for Best Foreign Language Film, but did not make the final shortlist.  It also won four Grand Bell Awards, including Best Film.

Supporting paragraphs: The Front Line (2011 film) Secret Reunion
Answer: Secret Reunion