3364
In November 2007 Singapore's SMRT Transit and  Hong Kong  's  MTR Corporation  Limited expressed interest in taking control of Melbourne's suburban rail network from Connex in November 2009 when their contract was to be reviewed .
 city of headquarters: Hong Kong, MTR Corporation
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: Hong Kong, MTR Corporation