6715
Adding fuel to the fire  Vale  chief executive Roger Agnelli said  last week  that Sudbury is the company's highest-cost operation and is n't sustainable at current prices levels .
 None
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:   
Answer:
 NA: Vale, last week