Saudi children of al-Fefi family walk up the stairs as they make their way to their schools through Fifa Mountain, in Jazan, south of Saudi Arabia, December 15, 2016. (Photo by Mohamed Al Hwaity/Reuters)

Habimana, 45, and her children walk to market to sell pottery on Idjwi island in the Democratic Republic of Congo, November 23, 2016. (Photo by Therese Di Campo/Reuters)

Muslim children play sack race during Eid-al-Fitr celebration in Taguig city, south of Manila July 18, 2015. (Photo by Romeo Ranoco/Reuters)

Children exercise before a wrestling practice session at an old Basque ball game gymnasium in downtown Havana, October 30, 2014. (Photo by Alexandre Meneghini/Reuters)

Children play football in front of an abandoned train compartment next to a railway track in Dhaka, in this May 29, 2014 file photo. (Photo by Andrew Biraj/Reuters)

Children look at Hares and Ducks ahead of the Turkey and dressed poultry auction at Chelford Market, northern England December 22, 2014. (Photo by Phil Noble/Reuters)

Children with balloons play beside the statue of British comedy legend Eric Morecambe on January 16, 2012 in Morecambe, England. According to scientists January 16, 2012 was “Blue Monday”, the most depressing day of the year. (Photo by Christopher Furlong/Getty Images)

Children play on a flooded highway during a summer downpour in Edsa, Quezon city, metro Manila, Philippines on April 25, 2018. (Photo by Dondi Tawatao/Reuters)