A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

A Christian worshipper reacts as she takes part in the Christian Orthodox Holy Fire ceremony at the Church of the Holy Sepulchre in Jerusalem's Old City, April 30, 2016. (Photo by Amir Cohen/Reuters)

Boys play with water as they celebrate Myanmar's New Year Water Festival of Thingyan in Yangon, April 13, 2016. (Photo by Soe Zeya Tun/Reuters)

Hungarian pole dancing champion Zsofia Komenda performs during the rehearsal of her unique show on a suspended pole in Budapest's Grand Circus, Hungary, June 17, 2016. (Photo by Laszlo Balogh/Reuters)

2016 Rio Olympics, Weightlifting, Final, Women's 63kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 9, 2016. Marina Rodriguez (CUB) of Cuba competes. (Photo by Stoyan Nenov/Reuters)

A towel with a print of the Nigerian naira is displayed for sale at a street market in the central business district in Nigeria's commercial capital Lagos February 4, 2016. (Photo by Akintunde Akinleye/Reuters)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

Some 1,250 students from the Assumption College flip their cards to form an image of Thailand's late King Bhumibol Adulyadej, in his honour, in Bangkok, Thailand, October 28, 2016. (Photo by Athit Perawongmetha/Reuters)