Ukrainian teenagers hit each other with pillows during a large pillow fight in downtown Kiev, Ukraine, 24 April 2016. About hundred people took part in the event “Pillow battle 2016” in Kiev. (Photo by Roman Pilipey/EPA)

South Korea's Amry Special Warfare Command (SWC) soldiers aim their machine guns in a frozen river during a winter exercise in Pyeongchang, South Korea, Thursday, January 8, 2015. About 200 SWC soldiers participated in this routine two-week winter drill. (Photo by Ahn Young-joon/AP Photo)

A woman protests her eviction from a building she and others invaded about a week ago in the Flamengo neighborhood of Rio de Janeiro, Brazil, Tuesday, April 14, 2015. Police dislodged squatters from the building slated for use as a luxury hotel for the 2016 Olympics in Rio de Janeiro. (Photo by Silvia Izquierdo/AP Photo)

This 1950s photo provided by the Estate of Vivian Maier and John Maloof Collection shows Maier in a self-portrait as she looks into a storefront wearing a hat in New York. New research about Maier shows the enigmatic Chicago nanny was obsessive about honing her skills as a photographer starting in 1950. (Photo by Vivian Maier/Estate of Vivian Maier and John Maloof Collection via AP Photo)

Passengers wearing protective masks travel on an over crowded train towards capital city, amid concerns about the spread of the coronavirus disease (COVID-19), in Colombo, Sri Lanka, July 8, 2020. (Photo by Dinuka Liyanawatte/Reuters)

People look at a dead pilot whale on a beach in Panadura on November 3, 2020. Rescuers and volunteers were racing since November 2 to save about 100 pilot whales stranded on Sri Lanka's western coast in the island nation's biggest-ever mass beaching. (Photo by Lakruwan Wanniarachchi/AFP Photo)

A robot, developed by start-up firm Asimov Robotics, holds a tray with face masks and sanitizer after the two robots were launched to spread awareness about the coronavirus, in Kochi, India, March 17, 2020. (Photo by Sivaram V/Reuters)

Students with torches protest against the alleged encroachment of Nepal border by India in far west of Nepal, during the 49th day of a lockdown imposed by the government amid concerns about the spread of the coronavirus disease (COVID-19), in Kathmandu, Nepal on May 11, 2020. (Photo by Navesh Chitrakar/Reuters)