165668
The aircraft is sometimes known as the Siemens-Schuckert Forssman R , the " R " alluding to the designation that the Idflieg assigned to multi-engine aircraft in late 1915 .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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