Definition: In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Input: Passage: He was selected as Sepahan's assistant coach in 2006 by Luka Bonacic. After Sepahan was unable to win the 200708 season and was ranked as runner up like AFC Champions League and winning Hazfi Cup in both 2006 and 2007, Bonacic was resigned as Sepahan's head coach and was appointed as Dubai based team, Al-Nasr Sports Club. He was selected Ghanbari as his first team assistant coach which was worked with him until his dismissal in February 2009. After he expired his contract with Al-Nasr, he became assistant manager of Sepahan for a second time under management of Amir Ghalenoei. He continue his career with Sepahan after Ghalenoie's resignation in 2011. Bonacic was appointed as Sepahan head coach for a second tensure and Ghanbari was one of his assistants. On 14 August 2011 and after Bonacic was sacked by club due to bad results, Ghanbari became caretaker manager of Sepahan. He was replaced with Zlatko Kranjcar after Sepahan was eliminated from Hazfi Cup. On 30 May 2012, he was named as Mansour Ebrahimzadeh's assistant coach in Naft Tehran. After Ebrahimzadeh signed as head coach of Rah Ahan, Ghanbari also signs a contract to become his assistant.
Link Information: On 28 May 2012, he signed a one-year contract with Naft Tehran. Answer: 1
Output:
How long was Ebrahimzadeh coach at Naft Tehran?