63831
In February 1946 , he wrote to John von Neumann , expressing his desire to build a computing machine .
 person: John von Neumann
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: John von Neumann 
Answer:
 person: John von Neumann