177917
Zhou Chi 's grandfather Zhou Pei ( 周沛 ) served as an advisory official in the Tang imperial government , while his father Zhou Ting ( 周頲 ) served as an imperial guard officer .
 Zhou Chi, Zhou, Zhou
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Zhou Chi, Zhou, Zhou