Men dressed as “Krampuss” prepare to parade at Munich's Christmas market, December 13, 2015. Young single men will wear the traditional attires known as “Krampusse”, consisting of animal skins and masks, with large cow-bells to make loud and frightening noises and parade through the city. They follow “Saint Nicholas” from house to house in December each year to bring luck to the good and punish the idle. (Photo by Michael Dalder/Reuters)

United States Air Force Academy graduates cheer as the United States Air Force Thunderbirds fly over the graduation for the Class of 2021 at Falcon Stadium on May 26, 2021 in Colorado Springs, Colorado. Chairman of the Joint Chiefs of Staff General Mark A. Milley gave the commencement address to the 1,019 graduates from the academy. (Photo by Michael Ciaglo/Getty Images)

A hiker admires the view as Mt. Etna, Europe's largest active volcano, erupts in the background, in the Bove Valley of Etna Park, on the eastern slope of Mt. Etna, in Sicily, southern Italy, Sunday, July 4, 2021. Since Feb. 16, 2021, Mt. Etna has begun a series of eruptive episodes. (Photo by Salvatore Allegra/AP Photo)

A man bathes in an ice hole in the Neva River in St. Petersburg, Russia, Wednesday, January 13, 2021. The temperature in St. Petersburg is –15C ( 5 °F). (Photo by Dmitri Lovetsky/AP Photo)

In this picture taken on January 21, 2021, people visit a nightclub in Wuhan, China's central Hubei province. (Photo by Hector Retamal/AFP Photo)

A woman takes photographs of falling snow from a window during a heavy snowfall, amid the coronavirus disease (COVID-19) pandemic in Seoul, South Korea, January 12, 2021. (Photo by Kim Hong-Ji/Reuters)

Spectators watch Austria's Stefan Kraft in action during the Viessmann FIS Ski Jumping World Cup Willingen on January 31, 2021 in Willingen, Germany. (Photo by Wolfgang Rattay/Reuters)

A protester carries a child march during a demonstration against the February 1 military coup in Yangon on February 10, 2021. (Photo by Ye Aung Thu/AFP Photo)