18050
In 1973 , he was made deputy head of the Anti-Terrorist Branch , where he became an expert on European terrorist groups such as Baader-Meinhof , and gave lectures on hostage negotiation and counter-terrorism tactics .
 Baader-Meinhof
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Baader-Meinhof