In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

Participants wearing superhero costumes attend the World DC Comics Super Heroes event in San Martin de Valdeiglesias, near Madrid, April 18, 2015. To celebrate the anniversary of the publication of the very first Superman story, DC Comics are asking fans to help set a new world record for the largest global gathering of people dressed as DC Comics Super Heroes. (Photo by Andrea Comas/Reuters)

A Nepalese devotee bows in front of a cow during the 'Gai Puja', also known as the Cow Worship Day, as part of the Tihar festival in Kathmandu, Nepal, 11 November 2015. The Tihar festival is the second most important event for Nepalese Hindus. During the celebrations people worship cows, considered the incarnation of Lord Laxmi, the god of wealth. (Photo by Narendra Shrestha/EPA)

Fishermen jump into a small river to catch trout as they celebrate Fischertag (Fisherman's Day) in downtown Memmingen, southern Germany, July 25, 2015. The annual Fisherman's Day (Fischertag) tradition goes back to the year of 1465 where every fisherman who were born in Memmingen tries to catch trout from the river. The participant who catches the biggest trout will be named the “Fisher King” for one year. (Photo by Michaela Rehle/Reuters)

A reveller covered in tomato pulp takes part in the annual “Tomatina” festival in the eastern town of Bunol, on August 30, 2017. The iconic fiesta – which celebrates its 72nd anniversary and is billed at “the world's biggest food fight” – has become a major draw for foreigners, in particular from Britain, Japan and the United States. (Photo by Jaime Reina/AFP Photo)

This photo taken on October 8, 2017 shows dancers posing in formation to celebrate the upcoming Party Congress, in Rongan in China' s southern Guangxi region. China will convene its 19 th Party Congress on October 18, state media said, a key meeting held every five years where President Xi Jinping is expected to receive a second term as the ruling Communist Party' s top leader. (Photo by AFP Photo/Stringer)

Visitors watch as Grigory Broverman, a member of the Cryophile winter swimmers club, pours a bucket of cold water over his 6-year-old daughter Liza during a flash mob, part of a celebration of Polar Bear Day at the Royev Ruchey Zoo in a suburb of the Siberian city of Krasnoyarsk, Russia, November 29, 2015. The air temperature was around minus 5 degrees Celsius. (Photo by Ilya Naymushin/Reuters)