6817
 Her father , William O. Ludwig of Aurora , Colo. , retired as the chief financial officer of the Holly Sugar Company in Colorado Springs and served in the Peace Corps from 1995 to 1997 in Sofia , Bulgaria , as a small-business consultant . 
 Sofia, Bulgaria; Bulgaria, Sofia
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: nationality, country capital, place of death, children, location contains, place of birth, place lived, administrative division of country, country of administrative divisions, company, neighborhood of, company founders 
Text: {0} 
Answer:
 Sofia, Bulgaria; Bulgaria, Sofia