174650
Wei Zhigu ( 魏知古 ) ( 647 – 715 ) , formally Duke Zhong of Liang ( 梁忠公 ) , was an official of the Chinese dynasty Tang Dynasty and Wu Zetian 's Zhou Dynasty , serving as a chancellor during the reigns of Emperor Ruizong and Emperor Xuanzong .
 Wei Zhigu, Wu Zetian, Emperor Ruizong, Emperor Xuanzong
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Wei Zhigu, Wu Zetian, Emperor Ruizong, Emperor Xuanzong