(FILES) This file photo taken on April 11, 2016 shows German President Joachim Gauck arriving to welcome the Mexican President at the presidential Bellevue palace in Berlin. Germany's 76-year-old president Joachim Gauck will not run for a second term next year because of health concerns and his age, the Bild newspaper said on June 4, 2016. / AFP PHOTO / TOBIAS SCHWARZ