A passenger not wearing pants sits in a subway train during the “No Pants Subway Ride” in Prague, Czech Republic, January 10, 2016. The event is an annual flash mob and occurs in different cities around the world in January, according to its organisers. (Photo by David W. Cerny/Reuters)

A participant jumps on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka, Czech Republic, February 20, 2016. (Photo by David W. Cerny/Reuters)

Participants wearing historical costumes ride their high-wheel bicycles during the annual penny farthing race in Prague, Czech Republic November 5, 2016. (Photo by David W. Cerny/Reuters)

Men work at Makala gold mine camp near the town of Mongbwalu in Ituri province, eastern Democratic Republic of Congo on April 7, 2018. (Photo by Goran Tomasevic/Reuters)

A participant dressed up in a costume attends the 2021 Prague Comic Con in Prague, Czech Republic, October 16, 2021. (Photo by David W. Cerny/Reuters)

Aleksandra Krunic, of Serbia, drops to the court after defeating Petra Kvitova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament, Saturday, August 30, 2014, in New York. (Photo by Kathy Willens/AP Photo)

A combination of pictures shows people taking photos of themselves in Tiananmen Square as they celebrate National Day marking the 67th anniversary of the founding of the People's Republic of China, in Beijing October 1, 2016. (Photo by Damir Sagolj/Reuters)

Mushers and theirs dog teams during the Sedivackuv long race, Orlicke Mountains, Czech Republic on January 28, 2016. The 240 Km (150 miles) race is a multi-day event, but was canceled today, two days early, because of poor snow conditions in the region. (Photo by David Tanecek/CTK via ZUMA Press)