14697
But according to U . S . officials , it now appears that North Korean engineers ran into technical problems in restarting the facilities .
 U . S, North Korean, U . S . officials, North Korean engineers, the facilities
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: organization, person, geographical social political, vehicle, location, weapon, facility 
Text: {0} 
Answer:
 U . S, North Korean, U . S . officials, North Korean engineers, the facilities