169808
Professional wrestling career Kallio was about 15 years old when Kallio and his father attended a professional wrestling event that featured Billy Sandow , a successful middleweight wrestler that participated in Barnstorming tours .
 Kallio, Kallio, Billy Sandow
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Kallio, Kallio, Billy Sandow