Given the input sentence, please extract the subject and object containing a certain relation in the sentence according to the following relation types, in the format of "relation1: word1, word2; relation2: word3, word4". Relations include: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

For example, two notable value investors operate businesses that fall into this category -- Tom Gayner at Markel and Warren Buffett at Berkshire Hathaway ( NYSE:BRK-A ) ( NYSE:BRK-B ) .

Answer: owned_by: Berkshire Hathaway, Warren Buffett; chief_executive_officer: Berkshire Hathaway, Warren Buffett; director_/_manager: Berkshire Hathaway, Warren Buffett; owner_of: Warren Buffett, Berkshire Hathaway; chairperson: Berkshire Hathaway, Warren Buffett