An East German civilian (L) shows an East German customs officer the contents of his Trabant (auto) at checkpoint Potsdamer Platz in East Berlin in this November 24, 1989 file picture, as East Germany enforcing stringent customs controls to avoid smuggling. (Photo by Reuters)

Zombie enthiusiasts gather near the broadcast tower at Alexanderplatz before setting out on a “Zombie Walk” in the city center on October 27, 2012 in Berlin, Germany. Approximately 150 zombies, who had organized themselves through Facebook, walked and limped across Alexanderplatz, growled and moaned at passersby and performed their jerking dances. (Photo by Sean Gallup)

A baby hippopotamus lies next to its mother on the first day it was presented to the public at the Zoo Berlin zoo on November 1, 2011 in Berlin, Germany. The baby hippo was born at the zoo on October 23. (Photo by Sean Gallup/Getty Images)

A group of scantily-clad women pose for photographs at the annual Venus erotic trade fair in Berlin, Germany on 12 October 2017. Venus Berlin is among the largest international erotic trade fairs, with more then 250 exhibitions from 40 countries and 30,000 visitors. (Photo by Alamy Live News)

BERLIN, GERMANY - NOVEMBER 11: Sculptor Oleg Bessonov creates a rosette from clay at the Schlossbauhuette studio where a team of sculptors is creating decorative elements for the facade of the Berliner Schloss city palace on November 11, 2011 in Berlin, Germany. The Berliner Schloss was the residence of the Prussian Kaiser and was among the major architectural landmarks of Berlin until it was heavily damaged by Allied bombing in 1945. The communist authorities of East Berlin demolished the building in the 1950s, and today's Berlin government is pursuing an ambitious project to rebuild the palace according to a design by Italian architect Franco Stella, which will recreate the facade of the building but with a modern interior at a cost of approximately EUR 590 million. The Humboldt Forum, the foundation leading the project, has given the Schlossbauhuette sculptors the formidable task of recreating the hundreds of architectural elements that decorated the facade, and though some original pieces were saved, more often the sculptors have only old black and white photos as reference. (Photo by Sean Gallup/Getty Images)

A woman on a bicycle rides past the remains of an Audi sedan set afire by an arsonist recently in Zehlendorf district in a street where two more cars were torched on August 23, 2011 in Berlin, Germany. Police have so far made no arrests in a series of arson attacks that have destroyed at least 70 cars within the last week and show no signs of abating. In recent years several hundred cars have been torched annually and police suspect left-wing radicals. The recent series of attacks, averaging about 10 a day, has been particularly severe. (Photo by Sean Gallup/Getty Images)

An Airbus A400M military aircraft lands at the ILA Berlin Air Show in Schoenefeld, south of Berlin, Germany, June 1, 2016. The Aerospace Exhibition at Schoenefeld Airport near Berlin takes place from June 1 till 4. (Photo by Fabrizio Bensch/Reuters)