Wounded people walk after clashes with riot police in central Kiev February 18, 2014. Ukrainian riot police advanced on the heart of 12-week-old protests against President Viktor Yanukovich on Tuesday and security forces set a deadline to end disturbances after at least five protesters were reported killed in a day of clashes. (Photo by Vlad Sode/Reuters)

Two men dressed as the Statue of Liberty look for tourists to pose with them for pictures in exchange for donations in New York's Times Square on January 20, 2015. (Photo by Jewel Samad/AFP Photo)

Italian disabled dancer Simona Atzori (top) performs, before a special audience with disabled athletes led by Pope Francis, in Paul VI hall at the Vatican October 4, 2014. (Photo by Tony Gentile/Reuters)

A sunflower “smiles” in a field in Tokyo on August 7, 2014. Some 20,000 sunflowers were enjoyed by visitors to the area this week. (Photo by Yoshikazu Tsuno/AFP Photo)

A protester wears a pig mask as he marches through the streets of downtown Vancouver with thousands of people participating in the Occupy Vancouver protest on October 15, 2011 in Vancouver, British Columbia, Canada. Thousands of people are taking to the streets in cities across the world today in demonstrations inspired by the Occupy Wall Street protest in New York City. An estimated 2,000 people participated in the Vancouver occupation. (Photo by Jeff Vinnick/Getty Images)

Mohamed Mostafa, 35, carries dyed yarns at a dye workshop in old Cairo, Egypt, March 17, 2016. Egypt's hard currency crisis and competition from modern factories in Asia and at home threaten one of the last dye workshops in Egypt. But one of its owners takes comfort in the trade's ancient resilience. Mohamed Mostafa boasts that the profession dates back 3,000 years, so it can survive anything. (Photo by Amr Abdallah Dalsh/Reuters)

Following a large air raid by German bombers, local people, coming out of their air raid shelters found a bus standing on end in a large crater, in Balham, London, October 15, 1940. (Photo by AP Photo)

People ride a prototype of a driverless vehicle as it is moves through a pedestrian area in Greenwich, east London, February 11, 2015. Britain has begun testing driverless cars in four cities, launching the first official trials ahead of a series of planned rule reviews to accommodate the new technology. (Photo by Suzanne Plunkett/Reuters)