278652
However , Professor Arpad Elo refused to award Valvo the rating he had earned , because Elo had never heard of Valvo and suspected that the tournament had been rigged .
 Arpad Elo, Valvo, Elo, Valvo
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Arpad Elo, Valvo, Elo, Valvo