12903
Enbridge  based in  Calgary  Alberta said it was preparing to remove the damaged section of pipe as its focus shifted to cleaning up the spilled oil which it estimates at gallons ( 3.1 million liters ) .
 city of headquarters: Enbridge, Calgary
Given options, please tell me the relationships of all the listed entity pairs.Output format is "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} 
 Entity Pairs:  Enbridge, Calgary 
Answer:
 city of headquarters: Enbridge, Calgary