223552
Together with the singer Christian Gerhaher he attended a master class with Dietrich Fischer-Dieskau in Berlin .
 Gerhaher, Dietrich Fischer-Dieskau
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Gerhaher, Dietrich Fischer-Dieskau