An injured boy who is undergoing surgery, after he was injured in what activists said was an airstrike by forces loyal to Syria's president Bashar al-Assad, rests inside a field hospital in the Douma neighborhood of Damascus, Syria December 5, 2015. Douma in Syria, an area controlled by rebels fighting to topple President Bashar al-Assad, has been shelled continuously for the past three years. The injured are taken to basements and shelters transformed into field hospitals run by medical staff who have stayed in the battered neighbourhood of Damascus. (Photo by Bassam Khabieh/Reuters)

People visit an art installation “Alley of Flying Umbrellas” in central St. Petersburg, Russia, May 15, 2015. Art installation inspired by “Umbrella Sky Project” of Portuguese town of Agueda and was made of 500 colored umbrellas. (Photo by Anatoly Maltsev/EPA)

Iranian demonstrators burn an Israeli flag during a rally marking al-Quds (Jerusalem) Day in Tehran July 10, 2015. (Photo by Reuters/Stringer/TIMA)

Elvis Presley tribute artist Bruce Stewart (L) of Georgian Bay, Ontario passes Lorenz Francke of Scarborough, Ontario during the four-day Collingwood Elvis Festival in Collingwood, Ontario July 25, 2015. Featuring over 120 Elvis tribute artists, it is the world's largest Elvis festival and last year hosted 30,000 visitors. (Photo by Chris Helgren/Reuters)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)

A student from the General Yermolov Cadet School takes part in weapons training during a two-day field exercise near the village of Sengileyevskoye, just outside the south Russian city of Stavropol April 13, 2014. The General Yermolov Cadet School in the southern Russian city of Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

Festival goer with phallus logo t-shirt during the Kanamara Matsuri Steel Phallus Festival at Kawasaki, Japan on April 2, 2017. The Kanamara Matsuri or Festival of the Steel Phallus is held on the first Sunday of April at the Kanayama shrine. The shrine celebrates a legend of a steel pen*s and was frequented by prostitutes who wished to pray for protection from sexually transmitted diseases. Visitors now wish for easy delivery, marriage and matrimonial harmony. Because of the large steel phallus the unusual festival has become a tourist attraction attracting many overseas visitors and is used to raise money for HIV charities. Phallus shaped candy, carved vegetables, decorations, and a big parade are all part of the festival. (Photo by DELETREE/SIPA Press/Rex Features/Shutterstock)

Revelers dance at the Old Settler's Music Festival in Driftwood, Texas, U.S. on April 22, 2017. (Photo by Mohammad Khursheed/Reuters)