Question: Per Mertesacker plays as a centre back for a professional football club in HIghbury, London, England, that has won how many league titles?
Sentence (from "FK Sarajevo"): Fudbalski klub Sarajevo (English: Sarajevo Football Club ) is a Bosnian professional football club based in Sarajevo, the capital city of Bosnia and Herzegovina and is one of the most successful clubs in the country.
Relevant evidence: No