What is the relationship between Syriza and ATHENS in the context of the input sentence. Choose an answer from: 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.

ATHENS - Greek politicians are preparing to vote on the terms of the country's third international bailout since 2010, which have split the ruling radical left Syriza party and met with a wary response in Berlin.

Answer: headquarters_location