A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

Chinese aids activists hand out condoms in a subway train in Wuhan, central China's Hubei province on December 1, 2014. The World Health Organization issued a call to action to China on December 1, 2014 over HIV/AIDS as government figures said nearly half a million people are living with the disease or its precursor, with hundreds of thousands more thought to be undiagnosed. (Photo by AFP Photo)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

A store mannequin with a protective mask stands before a clothes store as they open for the first time since March during the novel coronavirus (COVID-19) pandemic on April 22, 2020 in Berlin, Germany. Small to midsized-shops are opening across Germany this week as state authorities follow a recommendation by the federal government to ease restrictions imposed in March meant to slow the spread of the coronavirus. Some schools are also planning to reopen soon, as are museums and hair salons in coming weeks. (Photo by Maja Hitij/Getty Images)

A view of the Milky Way over the windmills at the wasteland of La Lora, in Rocamundo, region of Cantabria, northern Spain, 29 May 2022. (Photo by Pedro Puente Hoyos/EPA/EFE)

A tree covered with hoarfrost casts a shadow on a snowy field, shot with a drone in Sieversdorf-Hohenofen, Germany on January 31, 2021. (Photo by Patrick Pleul/dpa)

This photo released by North Korea's official Korean Central News Agency (KCNA) on June 7, 2012 shows North Korean leader Kim Jong-Un (C) surrounded by members of the Korean Children's Union (KCU) organizations during a joint national meeting to celebrate the 66th anniversary of the KCU organizations at Kim Il-Sung Stadium in Pyongyang on June 6, 2012. (Photo by AFP Photo/KCNA via KNS)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)