855
The  Royal Hong Kong Auxiliary Air Force  ( RHKAAF ) was an auxiliary unit of the United Kingdom Royal Air Force based in  Hong Kong  .
 city of headquarters: Royal Hong Kong Auxiliary Air Force, Hong Kong
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:
 city of headquarters: Royal Hong Kong Auxiliary Air Force, Hong Kong