A staff member wearing a face mask is seen at a shop in Berlin, capital of Germany, on April 29, 2020. Berlin made masks mandatory in stores on Wednesday, as the obligation to cover the mouth and nose has already been in force for public transportation since Monday. (Photo by Binh Truong/Xinhua)

Customers wearing face masks wait to enter a shop in Berlin, capital of Germany, April 29, 2020. Berlin made masks mandatory in stores on Wednesday, as the obligation to cover the mouth and nose has already been in force for public transportation since Monday. (Photo by Binh Truong/Xinhua)

A customer wearing a face mask selects clothes at a shop in Berlin, capital of Germany, on April 29, 2020. Berlin made masks mandatory in stores on Wednesday, as the obligation to cover the mouth and nose has already been in force for public transportation since Monday. (Photo by Binh Truong/Xinhua)

A sign reading "masks available" is seen outside a pharmacy in Berlin, capital of Germany, on April 29, 2020. Berlin made masks mandatory in stores on Wednesday, as the obligation to cover the mouth and nose has already been in force for public transportation since Monday. (Photo by Binh Truong/Xinhua)

A woman wearing a face mask leaves a shop in Berlin, capital of Germany, on April 29, 2020. Berlin made masks mandatory in stores on Wednesday, as the obligation to cover the mouth and nose has already been in force for public transportation since Monday. (Photo by Binh Truong/Xinhua)