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Through a sequence of team expansions reductions and relocations the  NHL  currently consists of 30 teams 23 of which are based in the  United States  and seven in Canada .
 country of headquarters: NHL, United States
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:  NHL, United States 
Answer:
 country of headquarters: NHL, United States