195770
The kraakdoos is a simple device , based around a single operational amplifier ( one of the earliest models to be produced ) and a few transistors , and can be easily constructed by someone with a basic understanding of electronics .
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Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
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