66887
During his international youth career , Ronaldo would go on to represent the under-15 team , under-17 , under-20 , under-21 , and under-23 national sides , amassing 34 youth caps and scoring 18 goals overall .
 Ronaldo
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Ronaldo