Task: Question Answering
Input (English): Passage: The movie begins with Huo Yuanjia fighting and defeating three Westerners: a British boxer, a Belgian lancer, and a Spanish fencer. While waiting for the fourth match to begin, Huo remembers his father Huo Endi teaching martial arts. The story is then told in an extended flashback. Watching his father fight, the young Yuanjia wants to participate, but his father is concerned about his asthma. Yuanjia sees his father in a match with Zhao, who dishonorably won by retaliating when Huo Endi held back a fatal blow. Humiliated by his father's defeat, Huo Yuanjia vows to regain the Huo family's honor and pride. He practices martial arts behind his father's back. As time goes by, Huo Yuanjia defeats several opponents (including Zhao's son) and becomes a famous martial artist in Tianjin. As he becomes successful, he grows arrogant and ruthless towards his opponents, unlike his late father who advocated showing mercy to opponents. This also leads to Huo gaining many followers and getting himself into financial trouble by spending his family's money on drinking and partying.
When a rival martial arts master named Qin Lei injures one of his followers, Huo feels insulted and confronts Qin on his birthday, at a restaurant owned by Huo's childhood friend, Nong Jinsun. Failing to dissuade his friend from fighting and fed up with his ruthless behavior, Jinsun ends his friendship with Huo. The confrontation escalates into a fight that ends with Qin's death. Qin's godson seeks vengeance and kills Huo's mother and daughter. Huo goes to Qin's house, where Qin's godson admits to the murders before killing himself. Huo learns that it was his follower who had insulted and provoked Qin, which caused Qin to beat him. 
Question: What's the full name of the person that Nong Jinsun's friend trained behind the back of?
Output (English): Huo Endi.