The Erster BÃ 1\/4 rgermeister is Hamburg 's Minister President . From the three eldest and juristic trained members the senate elected annually the First Mayor of Hamburg ( German title : Erster BÃ 1\/4 rgermeister der Freien und Hansestadt Hamburg ) -- the presiding head -- and his deputy ( Second Mayor of the Free and Hanseatic city of Hamburg , German title : Zweiter BÃ 1\/4 rgermeister der Freien und Hansestadt Hamburg ) .