292401
His longstanding interest is in analysis and translation of works by Karl Marx and Friedrich Engels , and the relation of those studies to Marxism and the Marxist tradition in social thought and methodology of the social sciences .
 person: Karl Marx; person: Friedrich Engels
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: Karl Marx, Friedrich Engels 
Answer:
 person: Karl Marx; person: Friedrich Engels