Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)

A protester clashes with a police officer in Athens' central Syntagma (Constitution) Square in this June 15, 2011 file photo. Greece triggered the regional financial crisis in 2009 when a far higher budget deficit than previously calculated emerged. The collapse of talks with creditors in Paris last November set off a month-long sequence of events leading to elections this week and proving Greece is still the region's weak link. The vote is expected to be won by Syriza, a far-left party opposed to the bailout, worrying investors and creditors alike. (Photo by Yannis Behrakis/Reuters)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

Japanese artist Megumi Igarashi, known as Rokudenashiko, holds her artwork after a news conference following a court appearance in Tokyo April 15, 2015. A Japanese artist on trial for obscenity after making figurines and a kayak modeled on her v*gina said on Wednesday that there was nothing wrong with her artwork and her arrest merely showed how far Japan remains behind the west. Words in the artwork read “Centre. 3D scan”. (Photo by Toru Hanai/Reuters)

A couple wearing masks as a precaution against the spread of the new coronavirus walk on the Malecon seawall at sunset in Havana, Cuba, Monday, August 31, 2020. Cuban authorities will introduce new measures starting tomorrow Tuesday aimed at containing the spread of the coronavirus in Havana among others a curfew from 7 pm until 5 am and no one without special permission will be able to enter or leave the province. The new measures will last at least 15 days. (Photo by Ramon Espinosa/AP Photo)

Vogue dancer Xiong Daiki, 22, takes a video of his team to promote vogue dancing, almost a year after the global outbreak of the coronavirus disease (COVID-19) in Wuhan, Hubei province, China on December 15, 2020. During lockdown, Daiki, his students and friends practiced at home in their bedrooms, staying in touch by sharing videos of new dance routines. (Photo by Aly Song/Reuters)

Students of Kiev's Olympic College perform during a rally in front of the Parliament building in Kiev, Ukraine, 15 September 2020. Students were protesting against the reorganization of the college, at risk of being closed, and the land where it rises which could end up for sale along with the facility's stadium. (Photo by Sergey Dolzhenko/EPA/EFE)

A policeman controls traffic at 42nd Street and 7th Avenue as New York City remains without electricity caused by a blackout that affected the entire city and most of the eastern part of the nation August 15, 2003 in New York, New York. More than 50 million people were affected by the outage, in Toronto, Detroit, Cleveland and New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)