3376
He studied physics from 1900 to 1905 at the  University of Berlin  under  Emil Warburg  and from 1909 worked with Heinrich Rubens .
 employee of: University of Berlin, Emil Warburg
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 employee of: University of Berlin, Emil Warburg