6652
Ralphs Grocery Company has contracts with the  United Food and Commercial Workers  the largest grocery union in the  United States  .
 country of headquarters: United Food and Commercial Workers, United States
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:
 country of headquarters: United Food and Commercial Workers, United States