166073
Over the course of the next few days , they visited Oxford – where Czar Alexander , King Frederick William and Marshal Blucher received honorary degrees – Woolwich Royal Arsenal , and a City of London banquet at the Guildhall on 18 June .
 Czar Alexander, Frederick
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Czar Alexander, Frederick