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.

John Chambers, the chief executive of Cisco, may not be as recognisable a name as Mark Zuckerberg or Jack Dorsey of Twitter (Xetra: A1W6XZ - news ) , but when he took charge of the networking equipment giant in 1995 the future bosses of Twitter and Facebook (NasdaqGS: FB - news ) were still in school.

Answer: founded_by: Facebook, Mark Zuckerberg; creator: Facebook, Mark Zuckerberg